Hertz rent a car

On 30 December I came from NZ to visit family in Cape Town. I rented a car from Hertz at Cape Town international. I rented the car for a month and asked the lady if I can bring the car back before the timeframe lapse and she said yes. After 26 days of having the car I filled up the car with petrol and took it for a full valet(which is the right thing to do). The next day while on my way to NZ I got a whole lot of charges to my credit, nearly R30000 in total, for who knows what. Only after 2 days I got an invoice but the amounts on the invoice does not even match the amounts taken from my credit card. When I looked at the invoice closely I saw I got charged a different rate as to why I signed for and also I was charged for petrol and kilometres, even though I did not exceed the amount of free kilometres. I made a complaint with my credit card company as well as with hertz. I have not heard anything from hertz even though it’s been more than a week, I sent 2 complaints. Hopefully my credit card company can do something about it. Needless to say, I won’t be making use of them again.