Calvary Portfolio Services ripoff Appears to be a fraud Phoenix Arizona

Sprint PCS has tried to bill me for services that I don't feel I owe. I sent Sprint a letter and they never responded. They sent the bill to a collection agency. I sent the agency a letter disputing it and never heard a word for almost 3 years. Now it has been sent to Calvary Portfolio Services. I have sent them a certified letter requesting validation of the debt. They have never responded and now have placed a collection account on my credit bureau's showing that the amount is in dispute. NO ONE has ever responded to my dispute. I have now sent Calvary Portfolio Services a demand letter (Certified) requesting that this be removed from my Bureau report. They have responded to nothing like I do not exist. I am not sure of my next move but the credit bureau wrote me and said that it was a valid debt. I have now sent copies of all my certified letters to the credit bureaus. I am now thinking of filing a suit in small claims court against Calvary Portfolio Services in violation of FDCPA laws concerning validation of a debt. I am looking for any ideas or suggestions. I don't want to pay this as I feel I do not owe it but no one will respnd to anything.

Michael
Chandler, Arizona
U.S.A.