Check Recoveries, Inc.

The saga continues, I received another call with a threat of a summons, called back spoke with one person then transferred to Tony Simms, I had spoken with him before, anyway I told him that I was receive a letter on their letterhead with thier address, I recieved a letter but only with the amount owed no address, anyway I had told I wanted validation of the debt, he said by the time they would get it to me I would be summoned, I guess I should just take my chances with the summons, since I am not receiving any info from these people. They threaten me with check fraud, which sounds really scarry, basically I get told a lot of thing by different people from this group, what should be my course of action? Thank you.