The best thing for you to do in this case is mail EC a certified letter containing copies of your payment receipts showing where you paid the loan off. Also, obtain a letter from the original creditor stating the loan is paid in full and include it with your letter. Once they have received it, they should verify the information, then back off, BUT that doesnt mean they will. They are extorting money from people that is not legally owed. They arent very smart over there, they are being sued by the Florida Attorney General and at the same time are continuing to collect debts in an illegal and abusive manner. If they dont back off once you have sent them the information, then you will need to contact a lawyer and explain it all to them in detail. Your documentation is proof enough that EC is illegally attempting to collect a debt. You should also file complaints with the BBB and the Florida and your state's attorney general. In the mean time, refuse all calls from them, hang up in their face if you have too and if they continue to harass you and keep calling back, tell them that you are recording their call, writing down the number of times they have called and will forward it to your attorney. If they argue the fact about the number of times they have called, tell them that it can be verified through phone records if need be. Good luck and dont let them bully you. EC are a bunch of liars and hopefully will be put out of business because of the lawsuit. It would be nice if criminal charges could be brought against them for instances like yours where they are trying to get money from someone who has paid their debt in full.