You need to send them a certified, return receipt debt validation, cease and desist calling, or "not me" letter (think of it as the best $6.47 you 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/
http://www.consumeradvocates.org/find-an-atto ... tates_value=All

Everything else you need to know follows including at least two agencies where you should report their criminal activities.

HARRIS & HARRIS, LTD

Web page with alleged contact info:  http://harriscollect.com/
BBB page gives them an A+ even though they have 103 complaints and 7 negative reviews (BBB removed 7 complaints to help them keep that A+):  http://www.bbb.org/chicago/business-reviews/c ... ago-il-88724008
Bloomberg lists the head criminals:  http://www.bloomberg.com/research/stocks/priv ... vcapId=61876620

Illinois Dept. of State info:
Entity Name    ARNOLD SCOTT HARRIS, P.C.     File Number    51126106
Status    ACTIVE
Entity Type    CORPORATION     Type of Corp    DOMESTIC BCA
Incorporation Date (Domestic)    03/29/1977     State    ILLINOIS
Agent Name    MS REGISTERED AGENT SERVICES     Agent Change Date    08/11/2010
Agent Street Address    191 N WACKER DR STE 1800     President Name & Address    ARNOLD S HARRIS 111 W JACKSON BLVD #400 CHICAGO IL 60604
Agent City    CHICAGO     Secretary Name & Address    ARNOLD S HARRIS SAME
Agent Zip    60606     Duration Date    PERPETUAL
Annual Report Filing Date    02/23/2015     For Year    2015
Assumed Name    INACTIVE - LASALLE ATTORNEYS, CHARTERED
INACTIVE - AFFILIATED LEGAL SERVICES, P.C.
INACTIVE - CREDITORS' LEGAL SERVICE, P.C.
INACTIVE - CHICAGO LAW GROUP, ATTORNEYS-AT-LAW
Old Corp Name    02/06/1987 - HARRIS & LEVIN, LTD.
02/28/1986 - ALLAN E. LEVIN & ASSOCIATES, LTD.
02/11/1997 - HARRIS & HARRIS, LTD.
11/09/1998 - ARNOLD S. HARRIS & ASSOCIATES, P.C.

Entity Name    HARRIS & HARRIS, LTD.     File Number    48645518
Status    ACTIVE
Entity Type    CORPORATION     Type of Corp    DOMESTIC BCA
Incorporation Date (Domestic)    04/29/1968     State    ILLINOIS
Agent Name    MS REGISTERED AGENT SERVICES     Agent Change Date    08/11/2010
Agent Street Address    191 N WACKER DR STE 1800     President Name & Address    ARNOLD S HARRIS 111 W JACKSON BLVD #400 CHICAGO IL 60604
Agent City    CHICAGO     Secretary Name & Address    DAVID L HARRIS SAME
Agent Zip    60606     Duration Date    PERPETUAL
Annual Report Filing Date    03/27/2015     For Year    2015
Assumed Name    INACTIVE - HARRIS & HARRIS, LTD.
ACTIVE - BALTA STRATEGIC INITIATIVES
Old Corp Name    01/02/1986 - BILCO CREDIT SERVICES, INC
12/01/1998 - BUSINESS CREDIT SERVICES, INC.
Illinois Bar Registration:
Full Licensed Name:     Arnold Scott Harris
Full Former name(s):     None
Date of Admission as Lawyer
by Illinois Supreme Court:     November 6, 1986
Registered Business Address:    Arnold Scott Harris, PC
111 W Jackson Blvd, Suite 600
Chicago, IL 60604-3517
Registered Business Phone:     (312) 423-7400
Illinois Registration Status:     Active and authorized to practice law  - Last Registered Year: 2016
Malpractice Insurance:
(Current as of date of registration;
consult attorney for further information)     In annual registration, attorney reported that he/she has malpractice coverage.
Public Record of Discipline
and Pending Proceedings:     None

Other complaints:
http://www.ripoffreport.com/r/Harris-Harris-Debt-Collectors/-Chicago-Illinois/Harris-Harris-Debt-Collectors-relentless-robo-calls-Chicago-Illinois-1209260
Employees are not happy:  https://www.glassdoor.com/Reviews/Harris-and-Harris-Reviews-E341083.htm
http://www.yelp.com/biz/arnold-scott-harris-pc-chicago
http://www.waynestrnad.info/communityissues/H ... encyExposed.htm

Looks like they were sued a lot:
http://caselaw.findlaw.com/us-7th-circuit/1578976.html
https://dockets.justia.com/docket/california/cacdce/2:2014cv09310/605512
http://www.law360.com/cases/4fe1ed89fb1ea720980042c2
http://www.leagle.com/decision/In%20FDCO%2020 ... 20HARRIS,%20LTD.
http://caselaw.findlaw.com/us-7th-circuit/1578976.html

It is incumbent upon them under the law to prove that the debt exists and that you owe it, and 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.

Read up on your rights here and also make a complaint at this government site:  http://www.consumerfinance.gov/

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

Also file a complaint with the Illinois BAR association.
https://www.iardc.org/howtorequest.html