Someone calling me regarding a payday loan already paid off

This morning I got a call from someone foreign, I could barely understand telling me they were going to arrest me at work, take legal action and have my lawyer call back if I didn't call. I called back to see what they were taking about and they said I defaulted on a payday loan and they were going to take action. Now I HAVE defaulted on a payday loan but already paid it back years ago. He preceded to list 5 payday lenders it could be, like he wasnt sure which one it was until I said it. I think one he said was FSM Marketing. If you remember Ellis & Crosby had taken over this payday lender a couple of years ago and they harrassed me because it went into default. I paid FSM back through another collection agency 2 years ago.... all of it... I told this guy I did not know what he was talking about and yes come and get me, he said was I prepared to be picked up at work, I said anytime! What is happening here, he said he got my social security number and name from one of the payday lenders... are they trying to pick up old names or something and try to get you to pay again for something you already paid? I AM SO MAD, I DO NOT WANT TO GO THROUGH THIS AGAIN AND BE HARRASSED. I have paid back everything!