Linda .... I should have recognized your writing style. What I think is that the worms have already escaped, the moment the collector started yanking your chain. From my reading of comments elsewhere, the ''block/ignore'' approach may be both inadequate and a loss of opportunity. I'm much more .. errrm, activist in my approach to nuisance callers than you, but hear this out.
FFR appears to be headquartered in Florida (non-shocker there) and have a current corporate filing there. This gives you something tangible unlike their South Asian fraudulent collector kin. The verbal threats you've heard almost certainly violate FDCPA and similar state laws. They are not aimed at you but at the alleged debtor, which limits FFR's liability to you. HOW-ever, you do have a cause of action for any abusive or harassing treatment you might receive. For the right damage award you can feel sufficiently frightened and abused, yes?
The only good reason for engaging with such thugs on the phone is to confirm the call source and gather evidence of lawbreaking. By far the most likely source of FDCPA violations will be in a verbal exchange. Let 'em rage at you all they like. You know you have the high ground and no fear of placing your assets at risk. Record the calls, save message copies, take richly detailed notes. When you're done toying with them, send the total cease-comm notice as I discuss in this other thread and see if the fools disobey:
My advice for a ''not me'' case, in a comment from 29 August 2012:
If you got 'em where you want them, send their worms back with a draft of your civil complaint and a cover letter ''inviting'' them to solve your problem for $x,xxx or you'll solve it yourself as Plaintiff.