I think that without that kind of evidence, they'd have a very tough time proving this in court, if you can convince the court that you never applied for the card, you never received the card, and you never used the card.  This is likely to either be relatively easy or very difficult, depending on the address that was used on the account, and whether or not you have any connection to that address.  Also, if you can show that it was impossible for you to have made a purchase that's part of the debt, for example from a store in Portland in the middle of a week you were out of the state and can prove it, you'll make your story much more believable.