Gulp. I thought everything was paid and then I get this letter in the mail today about some account that must date back a zillion years. I recall the CO and the amount. But I can't find my receipt. What can I do to get them to verify the debt , age, etc? It's not on any of my CR - so how do I get these people to leave me alone? Pay it? I will if necessary, but I feel like they're collecting on a receivable that has already been paid. I know this , I just don't have proof.