<prompt> Human: So I went to my gas station yesterday where I first attempted to use my card, which the system said it could not authorize. I then went to the person at the cash register, and she told me that they were only accepting cash that day because their system was down. So I gave her 20 in cash and went to go put gas in my car. When I got home and checked my card activity, the gas company had actually charged me on my card as well. Any tips on how to proceed from here? Assistant: Dispute charges with credit card company. Human: Ive never disputed a charge with my credit card company before. Dont I need some sort of proof to dispute the charge? I paid the 20 in cash so Im not sure how that will play out.Assistant: ity, the gas company had actually charged me on my card as well. AnYou can scan the receipt from the cash purchase and send it to your financial organization as proof that they double charged you when you dispute the credit card charges. Human: The cashier said that she couldnt give me the receipt because their system was down  <response>: She ripped you off. Id go file a police report on the cashier. 