Question regarding a response to a DV

I am trying to clean up my credit. Due to hard financial times a few years back, a lot of accounts got sold to various collections and debt collectors.

Got my credit report, and notice an entry on my CR for Capital One. Honestly, I do not recall having a Capital One card. Sent Capital One a DV. Letter had my name, current address (I had moved within the past year), and account number, as it was listed on my CR...wasn't the full number though (that's how Trans Union had it). I mailed it CRR to the address as listed on my CR.

Capital One's response today:
Quote:

Unfortunately, we are unable to process your request with the information you provided. So we can process your request, please fill out the form at the bottom of the letter. Send it, along with a copy of your previous correspondence, in the enclosed envelope to Capital One Service, Inc. PO Box 30285 Salt Lake City, UT 84130-0285.

The form asks for:

[quote]Name
Address on file with Capital One (Unsure, since as I stated I had moved. But I don't even RECALL a Capital One card!
Current Address:
Account Number Again, how should I know?
Social Security # I DO NOT want to provide a social to a company I am unsure of having business with!
Date of Birth: Again, DO NOT want to send personal info to a company I am unsure of having business with![/quote]

What are my next steps? How should I proceed? Thanks!!!!