Came back from the trip.Rented two cars from Avis Johannesburg airport and from Cape Town airport. Here goes my experience:
Avis Joburg- The guy at the reception tried to push for tyre insurance, windscreen insurance and what not which we kept denying.
Booked a Group A car, got a 1.1L Hyundai i10. The car was clean but highly underpowered. I really had to work the engine to get it up the slopes.
Returned the car full tank, took a picture of the fuel gauge(thankfully) , got it confirmed with the inspector and guess what got a refuelling charge of 3.5ltr along with a service charge in the invoice!! On sending the customer care the pic for the fuel gauge with the odometer reading they refunded the fuel amount but not the service charge.
Avis Cape Town - Lady at reception was pleasant, didn't push for anything extra. Gave us a free upgrade to Grand i10(Group B). Returned car full tank, invoice was as expected.
However, I got a charge of 22USD today on my credit card from Avis(i. e two weeks after return from South Africa). Not sure it is for which reservation, Cape town or Joburg. Checked for traffic fines, at their portal, nothing.Have sent mail to customer care again to know the cause. No response yet. Will have to raise a dispute if no justification is given. :(