They are not always sold.  Some companies decide to call an area code and then a prefix.  After that they start with 0001 and go to 9999 using the same area code and prefix.  It may not have been sold, especially when the caller is from afar.
If you kept getting calls from local places THEN your number has been sold.  Local places inquire about numbers in a certain geographic vicinity.  Your local pizza joint wouldn't do any good calling someone 2 states over about their new delivery service. They are the one that you need to look out for.

I have been receiving calls from these 'card services' telemarketers for over a year now. I have been blocking each number they have called with (over 35 at this point). And I have been filing complaints with the FTC Do Not Call Registry and the FCC complaint site, to no avail. I do suggest you all do the same, and do not talk to them or call them back.

But to really get some attention, I created a petition on the White House We The People site. Please go there and sign it, we have to get the word out any way we can:

http://wh.gov/pJ8s

Called me and I didn't answer. I never answer these numbers because I don't recognize the number. I always put them in my phone as DO NOT ANSWER and so far, none of those numbers have called me again, they just call from a different number. It's frustrating and I make a complaint to the FCC but it doesn't seem like anything is happening.

These idiots just don't give up with their survey scam. I've pushed the number asking them to stop calling and they still call. Reported it to the National Do Not Call List and the Kansas attorney general. I'm so fed up now that I push 1 and blow a whistle into the phone whenever this idiot answers it. Serves them right!!!!!!

I recieved 7 calls from this number between Dec 7th and 10th. I don't answer numbers that I don't recognize, so I let them go to voicemail. No message was left at any time.  My phone showed the call as coming from South Carolina.

They keep calling & every time I try & ask who they are or to stop calling they hang up on me.

Go away!

I continually get calls on my cell phone from 843-319-3526 telling me I can reduce my interest rate to 2%.  They say to press 1 to speak to a service person. When the service person answers they ask if I'm calling about reducing my intersst rate to 2% when I sany no that I just want my number removed from their call list they hang up!

This number called me twice with no one on the other end. What is going on?

If they called you guys then I don't see the point of *67 to block your number when trying to call them back since obviously that already have your number.   I called back without doing *67 and call doesn't go through.

I have received several calls from this number. I answered once and got an automated voice saying it was "card services". I immediately hung up since I do not have any credit cards but I continue to have incoming calls from them. I do not answer. Today I started getting calls for the same thing from a new number.

After a couple of years now of having this happen from probably over 50 different phone numbers by now, I'm finding the only thing you can do is change your phone number and NEVER give it to ANY business.

this number needs to stop call my cell phone

Save the offending number to your contacts under the name IGNORE-ME which will then show as your Caller-ID and you can then silence the phone :)

This number is now being used by the "Ann from Cardmember Services" group.  Report them, especially if they call your cell phone - that's a violation of FCC regulations regarding cell phone usage, as well as the Do Not Call Registry.  The more times they are reported, the more likely they are to have that # shut down.  Then THEY have to pay to get a new #!  Make it expensive enough, maybe they'll give up!

Calls 3 times per day, always hangs up, can never get them on the line to tell them to F off.  So here's what you do.  If you are on verizon, they now support blocking up to 5 numbers.  So if you keep getting called, log into verizon wireless, click on my verizon, verizon safeguards, then turn on the blocked call feature.  Enter up to 5 number of your choice, telemarketers, mother in law, etc, then apply the change.  No more calls from this number for me!

Trust me it does not work to call the number back. I tried and they called me 2x's in a few hours after I went through the automated system to be removed AGAIN..

I've got 3 calls from Nikki or Carol today, automated message telling me this is my last chance to take advantage of lowering my credit cards. When I try to call this number back, this is a false number that is not in service. One of the times, I was able to press #1 to be connected , but as soon as I started to ask to be removed, they hung up on me.

What can be done to stop these annoying calls??

"block this number" is now an essential phone feature and the last line of defense against the lowest form of telephone cretans.

You are taking the wrong approach.  Identify and contact the phone company that owns that number.  This is easily done by dialing the adjacent numbers until you get an answer.  Explain the situation and ask that person who their service provider is.  Contact that service provider and let them know that the number is the source of illegal calls. Once they know their service is being used for illegal activity, they must do something or be held liable for complicity in an illegal act.

I have been getting calls from this number MULTIPLE times a day and cant get anyone to talk to me even when i ask them about the offer, the REASON why they called in the first place.
I pretended to be interested and the rep hung up on me as soon as i asked what kind of company this was.

When I listen to it I hit 1, then a live man comes on and when I say my name and that you called me they hang up on me!!!!!

For those who comment "I'm on the Do Not Call list"... these people are criminals... they are scammers, trying to get your credit card number(s).  If they're calling your cell phone, investigate "block caller" and start adding these numbers to a dummy contact... you can't get them to stop by talking to them.  
Best thing you can do is to get as much information from them as you can and file a report with the Federal Trade Commision (FTC): http://www.ftc.gov/bcp/edu/microsites/robocalls/

These morons hung-up when I told them to remove me because I didn't have any credit cards for them to reduce the fees on! Idiots on my personal DNC listed cell phone.

Got the call and I disconnected it.

Your comparison of FTC complaints to the WALK button is incorrect. There are a few timing circuits working in parallel that control light changes and the button controls just one of them. The lights will change ultimately even if the button is NOT pressed. However, the FTC will NEVER investigate if no one files complaints so your comparison is wrong. Don't push button, lights will still change. Don't file complaint, FTC will NEVER investigate. Wrong comparison.

These creeps hang up just as soon as you ask to be romoved from their list.  I reported it to the FTC.   Ref 42354735

12-10-2012
This caller is still at it.
They called my cell phone and did not leave a message.

You know that button you push at a crosswalk to make the light change so you can cross?  That button doesn't do anything, the light will change anyway.  Just keeps you busy.  I'm reading all these comments about reporting phone numbers to the FCC and that thought came to mind.  Just sayin'