Disappointing service

I rented a car from Cape Town International to drive one way to Mossel Bay on 24 September 2022. This meant a double charge for a Group A car due to the long distance, which I did not have a problem with. What I feel was unreasonable was the double charge for the Sunday as well. I was informed that there is no way to return the car after 1200PM on Saturday as the Mossel Bay offices closed at 12:00PM, but when I took the car back the Monday morning, I discovered that there were in fact a facility available to drop the keys after hrs as a key deposit box were located at the Mossel Bay branch. Avis has been my preferred rental agency for many years now, but I am disappointed that I was charged double for an extra day were the car was just parked in my garage when I could in fact have handed it in the Same Day of my travel. This and the fact that my deposit has not yet been returned on my credit card, makes me feel uncomfortable to make use of Avis in future again.