Nissan south Africa is not transparent enough to first time car owners.

I bought a car last year may at bb group Silverton. When I bought the car the sales person did not explain to me about the additional costs that can be paid cash. I was also not informed to choose between a fixed interest rate or a fluctuating interest rate. When I took my car for a service at Nissan bb group they really over charged me. When I enquired with other independent garages they charge half the price that Nissan charges. Nissan is really ripping me apart wen it comes to charging. They told me that I should bring my car specifically to Nissan for a car service knowing well that they want to gain more money.