Afni Ripoff and Fraudulent Billing $1474.72 Bloomington Illinois

I received a collection bill from Afni inc, dated Jan 2, 2007 for the amount of $1474.72 from the original creditor " Verizon Communications, Inc." that was opened by someone else on my name back in 6/2000-9/2000 in West Covina, CA that I have never lived in.
I contacted Verizon to verify the phone number that is listed in the collection bill, but I was told that they cannot view past 3 years. Verizon representative told me to contact Afni for further info and also gave me Afni phone number that they have it in the list. I called Afni and I was very surprised to hear my SSN and my mother name. Where are all these infos come from ?. Is Verizon acting as a culprit for selling my personal info to 3rd parties ?.

After reading many other Afni ripoff reports, I know that this is a fraudulent billing. What should I do to dispute the debt and how to sue them ?.
Your suggestion or any detail info is greatly appreciated !

Chris
Northridge, California
U.S.A.