Promise that never been fulfilled

I purchased a 2015 Toyota Corolla 1.8 CVT from NTT Toyota Barberton in June 2015. I noticed that when driving downhill the rev counter on the car goes up to 5000rpm. This, however, is not a problem when driving on a flat open road. This therefore increases the fuel consumption and it's very annoying. I have reported this to the sales rep (Freddie Mkhatshwa) who referred me to the workshop manager (Andries). We took the car to Barberton on 14 July 2015 and the workshop manager drove the car. He said it is the first time he drove this particular model and was not aware about the rev counter issue. He recommended that the only solution to this is to put the car on a manual mode when driving downhill. Had we been told about the problem on this car, we would not have opted for an automatic vehicle but a manual vehicle. Changing a car to manual mode when the car is an automatic is not a solution to the problem. Could you please assist on this matter as this makes me not to enjoy the car. The noise from the engine is annoying and the consumption on the car is very high because of the rev counter. Mr duwenhage promise to bring Toyat specialist on the 18/08/2015 all in vain