Double payment

So I accidentally made a mistake by paying online with a card and paid the driver in cash, which he accepted! Only realised the mistake later on that day! Did log a complaint, can send proof, dates, times, witnesses! They are not cooperating! Saying it expired, no refund will be made, but logged the complaint the same day?! How does that work! Double payment! Honest mistake, why can't they rectify the problem? Investigate the driver? Please help, you can't just throw away money these times! Wilma, ***..?