Really now .... Unless your debt caller is a payday thug from overseas the FBI should not be interested. You'll get more legal satisfaction from the following:

If you are receiving repeated, misdirected, and/or abusive calls from a third party debt collector, you may find relief in the provisions of the FDCPA, the federal law which regulates collector behavior. Learn your rights at FTC-dot-gov. See also your state laws for additional support.
 Apr 13th, 2011
These fucking assholes are going down. I've got the FBI on their fucking ass, and they will do hard time in prison. FUCK YOU>
Joe Mama
 Apr 13th, 2011
They are harassing my 77 year old mother? I haven't lived there in over 30 years?
 May 22nd, 2009
Recorded message asking for someone who is not here. If you do not punch a number in 2 seconds you are being warned about a debt collection for that person. After that if you press a button you are being transferred.
Out of the blue call...
 Oct 13th, 2008
Garbled recorded message ????
 Dec 13th, 2007