Mrechants' Credit Guide Co. It isnt mine! Chicago Illinois

I received a letter in the mail from this company Merchants' Credit Guide Co. Supposedly; I have this bill that I have never been aware of. I have never had credit before, and it has never been on my credit report. I am assuming that it would have been on my credit report since it is allot of money.

I called the number on the letter, and was put on hold the first time till the line got disconnected. Then I called back and got a woman, and I started telling her about the letter, and got hung up on again! Then I called back a 3rd time and spoke with a gentleman by the name of Mr. Bazz.( who knows if it is real name)

I told Mr. Bazz about the letter, and gave him the account number that is on the letter, and I told him that I have no clue about this. He said that it was an account that was a visa account opened in 1998. I have never had Credit so this just blew me away.
Mr.Bazz told me to dispute it, and I am. But I dont know how to go about it.
Please help.

Thank you

Stormkitten
Malott, Washington
U.S.A.