Cavalry Portfolio Services, Same Story-They claim I owe money on acct. I never had with Sprint Hawthorne New York

I received a call in May that I owed money on an acct. that belonged to Sprint, but I have never done any business with Sprint. I don't even own a cell phone! I spoke to Sprint's fraud management dept. and they confirmed that I am not the person they're after & that they didn't even have a ss# on file for the person they are after. How then was Cavalry able to make a claim to the Credit Union?

I'm onto my second letter to them disputing the debt and am in the slow process of their run-around. I only noticed that they were still claiming that I owed them money after finding out that I had an adverse report on my credit report (Jun.)

I have now sent a dispute to them, the credit union, filed a complaint with the ftc, and the nydca.
What more can I do to get these bottom feeders off my back!

Thanks P. for SAMPLE LETTER FOR COLLECTION AGENCY TO VALIDATE CLAIM

J
New York, New York
U.S.A.