Car does not have power & radio does not play well

I bought a Toyota Corolla 2011 model registration at Toyota Rivonia in March 2014.<br> Since I had the car I have been complaining that it does not accelerate properly it has no power and the radio is not working properly (if I am driving an want to change between cd and Radio the radio goes off. I then have to stop and re start the car). I then took back in October 2014 where they said they could not find anything wrong if it starts again I must bring it back. Then we dealt with Allan who was very rude to my mom and said he was not God to determine the problem we need to explain clearly. How do I explain clearly if the car is not consistent on performance that it gives. The one day everything is fine the next it is not. They gave my mom another car for a week and did an inspection. The last time it was agreed that we will trade in the it was valued it was R140k and I indicated that I can pay another R20K. Which then takes it back to the original price of R160K which is what was paid for the Corolla.<br> When one buys a car that is still under warranty it is expected that problems encoutered are resolved. I have been taken from pillar t post. last email was 02/10/2015