Charging R4000 as a responsibility charge

Please do not use first car rental!!! I rented a car from them via my car insurance. They included a theft waiver and well as collision waiver which was included in the daily rate. Unfortunately the car was broken into and the tyre was ****** along will a pair of my shoes that were left in the car. I reported this to first car rental who swapped out the car for me then later sent me an email charging me for the loss of tyre which was approximately R1400, R 2200 for something called trim and R800 for handling fee. The more shocking charge was the R4000 they are charging me titled waiver. I called them to ask for an explanation of this waiver to which they said was a responsibility charge for not taking out the tyre waiver should anything happen to the car. I complained to them telephonically to the fores**** branch who directed me to send an email to their manager Gail about this. The email seems to be bouncing back and now I see they have reserved the money from my account. The call centre was useless with helping me understand the charge and so were the branch workers. The call centre agent even went as far to direct me to their website stating that the waiver that was taken is not really insurance and that I was still liable.