I'm not a lawyer, but I'd imagine that claiming that for cards that are legitimately yours would be considered fraud and would probably land you in more hot water than the initial debt would.
That'd be evidence if it can be tied to the original debtor, no?
I don’t recall, I’d have to look in my records, why don’t you send me whatever proof you have and I’ll if I can find anything?
These are pretty slimy businesses, they should be treated as such.
As far as the question of if something is or isn't fraud, why would the context matter? As far as I know fraud has nothing to do with perjury or being under oath. If you intentionally lie to a debt collector in order to get out of a legitimate debt, I think that would fit the definition of fraud.