AFTER 2 YEARS A BAD ACCOUNT - SUDDENLY???

I am contacted by Hammond Pole attorneys threatening me to pay within 3 days on a DA account ***. A month ago I asked for information as I ma not aware of this, last account paid in full with DA was more than 2 years ago, SUDDENLY through this debt collector I am in debt again but no payment history or details can be given. I have tried relentlessly to get through to DA just to hold at length on the automated system, to be cut off, to hold, to be cut. OMGOODNESS!! So I cannot confirm anything with DA but am harassed and threatened by your preferred debt collecting agency! DA you have never contacted me after I paid a final settlement on my loan and now all of a sudden I am contacted for bad debt. HOW DOES THIS work?? You have my details for a final payment which I made, but have NO contact details for me unless a debt collector can phone me. I am confused about what you are collecting, very agitated with the manner and totally frustrated with you company contact system which is ineffective. YOU HAND ME OVER to a DEBT COLLECTOR on grounds of what communication you had with me? NONE. This is ludicrous! Need someone to give me information.