Please do not given in to these callers.  I have been under attack for the past two years, they keep alternating their number and names.  When it began I was naive and I allowed them to bully me into making payments.  After paying a significant amount of money,  and not receiving the promised documentation.  I hired an attorney to receive the calls for me; I also reached out to the States Attorney's Office and filed a complaint with the FBI.  

My attorney and both the reps from the State's Attorney's office and the FBI field office told me it is a scam.  There is nothing you can do but wait it out and continue to stand firm.  As I stated I have been at this for two years now, initially it was two years.  It escalated when I refused to pay anymore money.  Now it happens every 3 to 6 months.

Unfortunately, I made a bad decision, and as a result I have learned a very expensive lesson.  It really boils down to a the following: 1) Pray for release from the trap (which is what I did); 2) For piece of mind - research the both the State and Federal laws regarding debt collection;  3) Check out the companies they say they are with (Look them upon the internet) and 4) Lasty and most important be willing to take a stand.

If you stick to your guns they will get tired and realize they cannot get to you.  Being educated about the laws will help you piece of mind as you make your stand.