I did the same thing at a Cracker Barrel once, except we only had our card and the tip would have defaulted to our waitress of record. So, we chose to leave the restaurant after paying our bill, drove to an atm, and returned with cash in hand for the girl who actually provided service to us. I think our original waitress got the message loud and clear. OP: I would have tipped nothing. You were more than generous in doing so.