Just go to your telephone company web site and BLOCK the offending number, so it will not be able to come thru.
But that's nothing permanent, because those Caller ID spoofers use a number for one day or so, then start to use some other number. The numbers they use are abandoned numbers, not yet reassigned by the telephone companies.
From Wikipedia:

Caller ID spoofing is the practice of causing the telephone network to display a number on the recipient's Caller ID display which is not that of the actual originating station. The term is commonly used to describe situations in which the motivation is considered malicious by the speaker or writer. Just as e-mail spoofing can make it appear that a message came from any e-mail address the sender chooses, Caller ID spoofing can make a call appear to have come from any phone number the caller wishes. Because of the high trust people tend to have in the Caller ID system, spoofing can call the system's value into question.

It is amazing that such a crooked practice is allowed to go on!
Where are the feds when I need them????? I wrote to my US Rep...no response!

Bottom line: IGNORE IT and never give the other side ANY information. PERIOD!

Just got a voice mail message to "hold the line" and then minutes of fuzzy silence...thought I could sorta make out voices. 'Glad I checked here!

They called my phone 22 times in 5 mins!!!!!  Really people get the message my phones set up on BLOCK!!!   I dont care how many times you call!!!!  I dont know you so GTF!!!

THe caller left a voice message about debt collection. No bills are in collection status here.
How did the call slip past the block list from National Do Not Call listiing?

From MCC, a Medical billing collection agency... I overpayed and they owed me $100. :)

Got the check in the mail today.

EHY ARE THEY CALLING ME

WHO IS THIS

Great I am glad it was good news for you. Congradulations too bad some of us are not quite that lucky , even though we are paying on the bill we owe they still want to try and sick collection agencies on us.  Thats ok if it keeps up I am going to turn it over to my attorney and let them deal with them.

Once again CONGRADULATIONS!!!

I got numerous calls from this number and now at my work. NOT OK!! I looked it up from my cell phone and found were they had left msg... Then looked it up on the internet.     It is a "Collections Agency"  = The true company name is "Quantum Credit Svc. and the phone number i was told to call back was 512-834-0448 and they told me it was Medi-Corp regarding a bill callers name was Sam in Austin."  He was polite i do have to say.  But the Actual name and address of this company is as follows : Quantum Credit Svc. 3307 Ranch Rd 620 N. Austin TX 78734-2107.  ( 800-522-8997) Austin Number is 512-834-0448.  

Just wanted to update yall on teh 800 number.

they are calling constantly looking for someone Ive never heard of. Ive told them before that I do not know that person please quit calling me and they dont!

Will not stop calling. I called back because I was tired of the calls and the automated system said they were closed. I don't answer calls from 800 numbers. They do not leave a company name in the automated voice mail. It is very annoying.

Just got this call. It's an automated voice that says "this call is for "Tiffany mylast" then it says "if this is Tiffany press 1 and if it's not Tiffany press 2". I pressed 2 and it then said "Have Tiffany call 1-800-522-8997 for an important business matter".
No way I'm I calling back that stupid place. if you wanna get a hold of me send me something in the mail!

toll free; unknown name; i've had 3 within 5 minutes; i'm ready to call a congressman

On 3/25/09 @ about 3:23pm (CA time), I recevied a call at my job employment from a Joan Hart, regarding a $200.00 payment to Elisa C. Mikko (Honolulu,HI).At first, she did not disclose the Collection Company she works for, as we all know that Collections Company state where they are calling from along with their name. She had informed me that she was calling regarding an account that I was not current with and demanded when I was going to make it current and why I am late. She wanted me to inform her of all this information. I asked again, which loan is she talking about, but should could not confirm the information that I was requesting, however, she said she would be able to fax documentation.  She also, could not provide me a Collection Account Number for the unpaid debt. Then, she told me I needed to tell her some type of information about this account, or else someone would be contacting my employer about this situation. After we completed our conversation and hung up, I started to think about the conversation in detail, and it didn't make sense.  Something didn't seem right or was a set up phone call. So, I went gut and I called back and spoke to another representative at this number and I provided all the information, SS #, B-day, Work Phone Number, My Full Name and my wife's First Name.  She confirmed that I had NO account what so ever. No Collections, nothing in their system, stating that I owe Elisa C Mikko any late payments. So we took it a step further and I had my wife call because it didn't seem right. This time no one answered the phone..All with a 30 min time frame. Somethings not right

They have called me five times over the last three days and have only left a message once. She said her name was Vicki Anderson and to call her back. I'm not going to unless they tell me in the message who their company is and what they want. Do they think I'm stupid?

So far I've gotten 2 calls from this number over the past week. The first one was at 1030 am on saturday and the message just said "Oh come on." and then disconnected! Then another call around 6 pm on monday and said to call Vicky Anderson. No company name or reason for calling, not even a please or thank you! They can call until hell freezes over for all I care. I've saved the number on my phone as "Do not answer."

why u call me?

Called and left a message stating Sam Stewart (no company name given) from Austin and to return his call.  Nothing further.

same here from a guy named sam no company name either and from austin. i called but no one picks up or anything.

called my home and my cell and left message to return the call ASAP. No company name on the caller ID.

I got the same message from a Sam Stewart in Austin.  Except when he called he said it was about my step-son and that it was very important.  I tried calling back but I got no answer.  Who ever this is, it seems very suspicious and I would not return the call if you get this message.  If it was someone credible they would tell you why they were calling and where they work at.

I got so tired of ignoring calls from this number that I finally answered my phone for a call from them.  This is a COLLECTION AGENCY regarding old medical bills.  Just so the rest of you know - don't answer unless you really want their spiel.

Called my cell at 0800 (AM) - "I answered because I was sleeping, I normally will NOT answer an 800 number - but I did not talk.  A women said she was Theresa and it was critical that I return a call to a number and extension I do not recall.  There was no company name or anything.  I am a 30 year retired Military, service connected disabled Vet (65) and I had a problem where Tricare (a ripoff for GIs by Reagan) refused to pay the full charge at a local hospital and they have tried, illegally for years to get the difference.  I suspect this is a collection agency - maybe here in Austin.

calling over an over i will not answer a 800 number

This place is calling my work! And not even my extension or for that matter even my office!! They are calling the freaking auditors office instead! What is wrong with these people! They NEVER leave a mess on my cell, when I think they call but to leave it at work on a voicemail that's not even mine...come on here folks!

I've left an earlier message received on my HOME phone.  This time they called my cell phone.  No name, no company, just an ID number of my call back - and a number to call. My cell phone really irks me.  They have never called that before - I will be sure not to answer the next time.  As I said earlier, I am certain it is about a medical bill.  BTW - I said before that this is a Tricare mess, and recently Tricare sent me $165.00 that I opverpaid for Med Bills, but these people are still trying to get m,oney they claim Tricare wouldn't pay, and I need to pay it.

Called from number 314-314-5125, a lady saying her name was Myra Strong, and she needed to speak to me that it was important, and to call her back at 1-800-522-8997.

The voicemail I received gave the name Joan Hart, the phone number to call back and nothing else.

I got a call from this number on March 27th with the call back number and to press 1 if it was me and if not to call them and tell them how to get a hold of me. Gave a Reference number for "whoever calls back." Got another call this morning, March 31, and it was a woman who talked very fast. She said her name (Keely?) and the 800#, nothing else.

Now it's "Aurelia Garza."