800-361-0363

Except scammers like this NEVER send anything in the mail to validate what is quite likely a non-existent debt.

I would either ignore them or tell them to Stop Calling, that youve reported them to the FCRA, and report them.  Then send them a certified letter demanding to see the Original paper work, as you dont owe what theyre claiming you owe. Also tell them to remove this from your credit immediately, or if it isnt on there,, that if they put snything on your credit, youll report them and may seek legal action.

Rosenthal Morgan & Thomas, trying to sound like a law firm, waiting for a summons from them.

You will need to send them a certified, return receipt debt validation (by law they have to go back to the original creditor to prove you owe the debt), cease and desist calling, or "not me" letter (this will be the best money that you have ever invested).  Also send it first class mail in case no one will sign for it.  Make a notation of that fact at the bottom of the letter.  You also need to report them to the proper agencies to which I have provided links to.  Then you need to go out and get a consumer lawyer to sue them on a contingency basis (no money out of your pocket) and let them pay you for the harassment.  If everyone did these three things, these crooks would be bankrupt, and we would all be the richer for it.  Use these web sites to find an attorney in your state that will probably take the case on a contingency basis (no money out of your pocket up front):
http://www.consumeradvocates.org/find-an-atto ... tates_value=All

Everything else you need to know follows including at least two or more federal and state agencies where you should report their criminal activities.

ROSENTHAL MORGAN & THOMAS INC

Website lists them in Missouri and a member of the ACA, one of the support organizations for these criminals: http://rmtcollects.com/

BBB gives them an A+ rating with 12 complaints (BBB removed 12 complaints) and 9 negative reviews as of 11/17/2021:  https://www.bbb.org/stlouis/business-reviews/ ... is-mo-110225656

Missouri Dept. of State info:
Name(s)     ROSENTHAL, MORGAN AND THOMAS, INC.     Address
12747 Olive Blvd Suite 250
Saint Louis, MO 63141
Type     Gen. Business - For Profit     Charter No.     00519408
Domesticity     Domestic
Registered Agent     JULIUS T. DAVID
12747 Olive Blvd Suite 250
Saint Louis, MO 63141     Status     Good Standing
        Date Formed     3/21/2003

Duration     Perpetual

Renewal Month     April

Report Due     7/31/2018

Other complaints:
https://rosenthal-morgan-and-thomas.pissedconsumer.com/review.html
https://www.creditreportproblems.com/rosenthal-morgan-thomas.htm
https://whocallsme.com/Phone-Number.aspx/3147860070

Looks like they get sued a lot:
https://www.scribd.com/document/162761309/Pao ... mplaint-Lawsuit
https://www.courtlistener.com/docket/4128879/ ... and-thomas-inc/
https://www.pacermonitor.com/public/case/1976 ... and_Thomas,_Inc
https://dockets.justia.com/docket/indiana/insdce/1:2015cv00548/57836

It is incumbent upon them under the law to prove that the debt exists and that you owe it, and (this is the important part) that they have the legal right to collect it.  You are not obligated under the law to prove that you don’t owe or that it is paid.  

Federal law (FDCPA) requires them to send you a letter (US MAIL ONLY) postmarked within 5 days of their first contact that contains their name, physical address, the creditor’s name, and the amount of the alleged debt. It also must contains “mini-Miranda” telling you that it is an attempt to collect a debt and that all information will be used for those purposes.  The one other important thing that this letter must also have in it is that you have a right to dispute the debt within 30 days of receipt of the letter and if you do so, all collection activity must be stopped until the debt is verified.  If and when you get that letter you should immediately send that debt validation letter by certified, return receipt mail.

First, you should make a complaint at this Federal Agency, and while there you should also read up on how debt collection is supposed to work as well as what your rights in this matter are: https://www.consumerfinance.gov/

Also file complaints with the FTC: https://www.ftccomplaintassistant.gov/#crnt&panel1-1

Also file a complaint with your State Attorney General's office.
List of State AG’s offices:   https://800notes.com/faq/attorney-general