Poor service

My Insurance rented a car on my behalf from this company, unfortunately when i was at the mall i came back to a scratch on the back passenger. When i returned the car i advised them of the situation now i am being charged over R3 000.00 for scratch that was not even my fault. I even got a quote from a panel beater and they advised its a minor scratch. now they are refusing to pay me my deposit. i find the bad business practise and them always trying to ***** clients deposits.