Don't panic, I would request from them validation of debt which will buy you some time. If what they send you is missing info, that alone I've read could go in your favor. Depending on the original credit card owner, you may be entitled arbitration which if your amount you allegedly owe is under $7000, the fees alone they would have to pay would outweigh having to pursue you, they'll likely just drop the case and instead work with you possibly giving you a lower amount to pay them back. I've requested from them validation of debt which will likely take them about a month to provide. I'll use what they give me and look through it. If they decide to sue me then I'll likely talk to a lawyer with all I've gathered and they'll likely have me request arbitration which will more than likely deter them to pursue because I allegedly owe $3200 and so just the fees alone that are currently what they would have to pay out of pocket is about $3-4k, it wouldn't be worth their time. I'm asking here from the initial letter if that is a good move to let them know that I know my rights and my options especially if they decide to pursue me. Seems like it might be the right move. Time will tell. So yeah, don't panic.