POOR SERVICE FROM AVIS

I hired a polo vivo with Avis at Isando branch through travel solutions agency, pick up date was 30.06.2022 and drop off was 07.07.2022, i dropped off the car according to my contract and they inspected the car and said the was nothing wrong with the car and that i can go, there was however an upfront deposit due to the company prior to me (renter) receiving the keys, after i dropped the car they told they will process my refund since there were no damages to the car. On 08.07.2022 i received a call from my agency telling me that Avis say that i have not returned the car according to my contract date of return, i explained to my agent that the car was returned, he then followed it up with Avis and it turned out that someone forgot to mark the car as "returned " on the system, Today on 12.07.2022 i got news from my agent saying he got an invoice from Avis that states i have returned the car "very dirty", when actually the lady who expected the car saw the car and i was with her the car was cleaned and on the invoice i was charged a lousy R500 for car cleaning when the car was returned clean and i was with the inspector nothing was mentioned to me that the car was "very dirty".