******* FUEL CHARGES ON MY BILL. ISSUE NOT RESOLVED ALMOST A MONTH LATER

I lodged a complaint and the issue is till not resolved. The incident happened beginning of December. They stole from me. They charged me incorrect fuel charges and my money has still not been refunded. I am being told the car tracking device shows that the rental didn't go anywhere after I dropped it off but the fuel tank was full to capacity when I dropped it off but they charged me 15litres. Like for what? And how is that even possible? They are *******.