I had an issue with XXXX Wireless.  It got nasty; I wrote a letter to the XXXX, sent a copy with a note to the President XXXX.  The result was that all the XXXX billing was taken away, and I got a XXXX+ credit on my Wireless account.  I suddenly got a letter from MRS BPO, L.L.C. stating they were collecting XXXX for XXXX.  No one at XXXX knows anything about it. My current bills do not indicate the amount. I don't want my credit ruined by these people and no one knows who authorized the collection agency to come after me.  XXXX.