Normally things like this that come in the mail fall under the Postmasters domain. You can file a report on this here:
Postal Service Inspectors:
https://postalinspectors.uspis.gov/forms/MailFraudComplaint.aspx

Or take it to your local Postmaster.

With this being along the lines of IRS/Extortion Scam, it probably should be reported to that States Attorney General, their State Revenue Dept and the FBI as well as the FTC.  The threats are in violation of the FDCPA laws.

Please do file reports with the FBI, your state attorney general and Department Of Justice,FTC & FCC..

http://www.ic3.gov/default.aspx
http://www.fbi.gov/
https://www.ftccomplaintassistant.gov/#&panel1-1
https://esupport.fcc.gov/ccmsforms/form1088.action
http://www.consumerfinance.gov/complaint/

Also read up on the laws and your rights:

http://800notes.com/arts/Jb8EW-eDhQA/harassin ... ou-need-to-know
http://www.ftc.gov/os/statutes/fdcpajump.shtm
http://www.consumerfinance.gov/askcfpb/search ...
http://www.consumer.ftc.gov/articles/pdf-0096-fair-credit-reporting-act.pdf

And see:

http://800notes.com/forum/ta-86217073a9c8dad/ ... 077595690349410
************
http://www.consumer.ftc.gov/articles/0258-fake-debt-collectors
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http://www.deadiversion.usdoj.gov/pubs/pressreleases/extortion_scam.htm

Keep receiving letters, first from the supposed "MO Dept of revenue" then from a T. Jones for GC Services, for over $1100 in "delinquent income taxes" from 2009.  I didn't live or work in Missouri in 2009, so that's not in any way possible.  The very first letter I received said that the period for dispute was over and threatened to take my personal property if the debt was not collected in 10 days!  Scammer scare tactic!  I looked up the number for the "dept of revenue" and it was listed as a mobile number.  Sorry but state offices don't use cell phones in their office.  Crazy.

Received my letter in the mail today from "T. Jones".  Says I owe $42,576.42 in state income tax.  Didn't live in Missouri in the tax year stated on the letter and certainly didn't have any Missouri sourced income.  Gosh, didn't even make that much in the state I did live in. Stationary wasn't even consistent from the letter to the two envelopes that came with it.  Different PO box on the letter from the remittance envelope.  Letter didn't say "LP" but the envelope did.   A scam!!!  

I also got a letter from GC services from T. Jones stating that I owe $1900, When I called the phone number it went voice message asked me leave the account number.It is terribly fraud.

I had a voice mail from this number and it was a lady saying her name was Mrs. Fuller and her ext. is 0033 and all she said in the voice mail and said it was about a personal business matter and nothing else.

Got a letter from gcs that said i owed a past sales tax debt of over$5000.00 from a business I have not owned in more than 10 years. They said they wanted$1250 up front and the rest in 9 months. Reading all of these comments memories me real sceptical of paying them a dime.

Received the same letter everyone else has.
Claims that I owe nearly $5,000 to the Missouri Department of Revenue.
From T. Jones.

SCAM!

Received the same letter in PA and I have never even been to MO.  This is a phishing scam.  This outfit is trying to scare people into paying a bill that they do not actually owe.  You should contact your local police and your state's Attorney General's office to report this fraud.  If you are contacted again, demand that they provide verification of the debt and tell them that they do not have permission to contact you unless it is to notify you that they are ceasing collection.

Just received a letter from GC Services, from T. Jones.  When I called the number 888-817-4957, all the voicemail said was continue to hold.  What a scam company.  What company does not even announce it's name?

I am writing a letter.  Left MO years ago and won't ever ever EVER go back.

This is Albert Gasiton
This is not a solicitation or marketing call.
Call back: Re case # ,,, ect,, ect,,

Yea this call made no since to me. I called the number and he couldnt tell me what business or the companys name was. Sounds fishy .. then he asked for my social securety number.. lol.. thats when told him to send it on paper and I dont just give my ssn out.  It sounds like a SCAM.

Got a letter from a company called GC Services with this same phone number and said we had been turned over to this collection agency. I have a bill from the Missouri Dept. of Revenue and was going to pay the 4th Wednesday. I just reeived a statement 1 week ago and now I'm in collection!!! What is going on! I called this number 1-888817-4957 and it just says leave your number.

Larry Rawson

This number belongs to GC Services, a collection agency. They will lie and tell you they are with the state.

Never ignore a dunning letter. I mean never .... It should have language giving you a thirty day window in which to dispute the claim. Do that before time runs out, even if you partly agree with the claim, with a validation request sent via USPS CMRR. If there is no "miranda" paragraph about disputing, dispute anyway and note their omission as a legal violation.

GCS is a known lawbreaker like many of its collection industry peers. If you don't preserve your rights soon enough you may be chasing them at a sprint in a courtroom. Before sending that letter you can of course wait for a few phone calls to come in and document them carefully for violations of relevant laws.

Chiefly you'd look at FDCPA, which regulates industry behavior. TCPA sometimes can play too, with automated calls to mobile phones. Living in Cally you are fortunate to have the Rosenthal Act, which applies pretty much a copy of FDCPA to original creditors. GCS is third party, but it's always good to know your state laws.

Learn how to exercise your FDCPA rights as an alleged debtor at FTC-dot-gov.
http://www.ftc.gov/os/statutes/fdcpajump.shtm

I got the same letter from T. Jones of GC services out in Jefferson City, MO.  They also claim to contracted by the Missouri Department of Revenue.  Should I even response to their claim of tax owed?  I live in California.

I got a letter from a Guy called T. Jones from GC Service, P.O. Box 3488, Jefferson City, MO 65105-3488, Tel: 888-817-4957 begin_of_the_skype_highlighting              888-817-4957      end_of_the_skype_highlighting.

They said that I should pay $10,002.8 to Missouri Department of Revenue with State of Missouri contract # C 305080002.

I never have been in Missouri and have no any business contact with Missouri.

Never trust them, they are thefter and liers.

Yes, Albert Gattison will lie to you and tell you that he is with the State of Missouri, when he isn't.  He is a bill collector and he, at least in my situation, had ALL of his facts wrong.  Don't buy it. He is just a bill collector that apparently is willing to say whatever to get you believe that he works for the so and so and that you owe so and so--even when you don't .

This is Albert Gasiton
This is not a solicitation or marketing call.
Call back: Re case # 14623102 phone 888-817-4957

Since this made no sense to be left as a VM
He did not state a company name.
No mention of time zone or when to call back.

We are treating this as a SCAM