Afni Inc. — Bogus phone bill!

Today I received a settlement letter stating that I owed verizon 123.90 for a phone service I never applied for. I was not aware of this matter until I received a letter asking me to pay of a disconnected phone bill. Apparently I had a phone put in my name and the account is past due and verizon has turned this account over to this collection agency. I have never applied for this account nor does this company have the correct spelling of my name. They spelled my name Coletta Sacosa. The account number shows up in the collection agency records how do I fight this company for taking fraudulent actions against me? Plz advise smb!