Bad, bad people...

I suggest taping the conversation (let them know you are) and request they send you documentation validating the debt they are attempting to collect.  Under no circumstances should you send these people any money - they have proven repeatedly it is a scam.  Keep your cool...

Familiarize yourself with the federal law pertaining to debt collection (http://www.ftc.gov/os/statutes/fdcpa/fdcpact.htm).  If after speaking with the representative you feel as though they violated the statutes by threatening arrest and/or threatening or actually contacting your employer, contact the Florida Attorney General's office and the Federal Trade Commission (www.ftc.gov).    

The Florida Attorney General's office is currently suing the group associated with this phone number (http://myfloridalegal.com/__852562220065EE67. ... bass,associates).  You can file an online complaint at http://myfloridalegal.com/contact.nsf/contact.

Good luck!