<prompt> Human: A restaurant is charging me 60 gratuity on a meal. I paid the meal via credit card and tipped in cash. The receipt they have on file says cash on the gratuity line. I already disputed this but CapitalOne wants me to prove that I paid in cash. The receipt alone was not enough. Has anyone done this before? Im at a loss here on what is appropriate supporting documentation on a cash tip. Updates. Thank you for all the responses. Its been really helpful and Ill call them again with all of this in mind: This dispute was initially resolved when CapitalOne caught the tip and notified me it appeared fraudulent. It was removed from my account after I followed up. A few months later, the merchant has filed the charge again and insists its a valid charge. CapitalOne sent a letter stating So for now, we are reapplying the charge to your account, and it will appear on your next one to two billing statements. Ive called them before about this and they insisted that it was just standard procedure. I just dont know how to follow this procedure because it was a tip in cash. Its basically my tables word against the restaurants. Ill follow up with asking for a supervisor. Im just hesitant to make ultimatums because I liked my CapitalOne card before this. I chose it because it had some of the best benefits for a VISA card with no annual fee.  <response>: I personally would call CapitalOne back and ask to speak with a manager. 