These people called "First IRS" keep calling me. They think I owe them money--(I don't). I sent them a certified letter requeting debt validation. The letter sat in their P.O. box for about 2 weeks --they never signed for it, so the certified letter was returned. I do have all the reciepts that I mailed the certified letter to them, and the USPS has all the tracking records that the letter was delivered, but they never signed for the letter, so of course they haven't validated any debt. However, they do keep calling. How do I deal with these rootie booties?