AFNI, Inc. trying to collect an old Verizon Debt Bloomington Illinois

Is anyone else having a horrible time with this junk collector AFNI, Inc.? I found all three credit reports had this new posting from AFNI, Inc. and I had never received one single thing from them. All of the sudden, about three months after my credit report postings, I get this letter from them, with an old Verizon bill for a phone number I never had! I am absolutely positive this was never my phone number. I even asked my two grown kids, and they said never did we have this number.
I feel as though AFNI has me because they have this so called proof. Verizon won't tell you anything about an account that was given to a collector they said. This was apparently from way back in 2005. I just wondered if anyone has some advice for me? I sent disputes to all three credit reporting agencies, and they all came back as having verified this information with AFNI. That does alot of good if AFNI might even be doctoring old Verizon bills to make them look real.

Julie s.
Abingdon, Maryland
U.S.A.