I would contact the seller and see if they acknowledge the problem and what they are willing to do. In some cases it may be that there is some residual value for the card you received in which case a partial refund might be negotiated with you keeping the card, in other instances it may be that you have no use for the item and strictly want a refund, which again they may also be willing to do. This was exactly the problem I had in trying to get my 2004 Cracker Jack Mini Blue Alex Rodriguez card, the SP is card number 17 while the more common card which I already had is unnumbered. The seller listed it as the SP, but when it arrived it had no number. The seller was okay with a return for refund rather than a reduced cost, and I couldn't negotiate postage costs, but it was a respectable outcome that was in line with what I would have had if I had filed a claim.