Abuse of customer credit card - non-disclosure of costs when debiting a credit card

I was debited for damages without Avis disclosing what the costs of damage were. I don't know if they use customers to upgrade their vehicles. On return of the vehicle Avis said they would send me a quotation for the mud slip and fender liner that was damaged. But that does not cost R9100 on a Toyota Corolla cross. I contacted Toyota and parts and labour is not more R3500. What is Avis doing?