A collection from them posted to my credit report this weekend as well, if anyone comes in with contact info please send it to me as well thanks. My collection is also from AT&T it was originally with AFNI then AFNI just disappeared form my credit report so I thought I was in the clear for a while on this. Yeah right. Sorry I didn't have anything helpful to add.
Oh, from what I've read on them so far, they are a sticky collection agency that is hard to get the delete from and won't do PDF in writing, and only sometimes follow through on their end of the bargain on PDF negotiated over the phone. Sucks but good luck