They charge for refuelling even if if you have filled up the fuel tank

I rented a car from budget car rentals Durban airport on the 28 April and returned it the 2nd of May 2025. When returning the car we made sure to refill it at a Sasol near the airport. I later received an invoice that I have not refilled the car and was charged R550 for refuelling. I send a screenshot of the purchase from my Apple Pay for them to see a time diffefence and they say it’s not enough proof as they not sure it’s for refuelling . They charged me for other things I cannot explain and not agreed on . It is 18 days later and I still have not received my deposit, which was R3500.