Validation of debt from "collector" of payday loan

I have received a call from a company called Capital Harris Miller and Assoc
stating that they will serve me unless I put a prepaid debit card on file with them
and setup payment arrangements....for a VIP Cash payday loan from last year.

Im from California.

So to give me time to do research on them, I asked them to email me
proof to validate that they really own the debt .

The pdf file they emailed basically just stated VIP Cash as the original payday company and my original account number.

I have been scammed by a couple of "collectors" or "mediary" companies already
who somehow had all my info and payday account numbers.

So basically, I am wondering if them having the original account number is
REALLY enough to be considered validating the debt or proof that they own the debt?

Please let me know.

Thanks!