Bad customer service

My first complaint is a pressure crack on my windscreen which Audi is not taking responsibility for even though the vehicle is still under warranty until March 2017. The matter was first brought to their attention mid November and still nothing has been resolved. Then my vehicle with only 38000km broke down on the 17th December due to a steering fault and had to be towed to Audi Claremont, where it still is 3 weeks down the line. I have had very little communication from them, phone calls have not been returned after leaving messages and I have encountered a bad attitude from the staff. Today I emailed Audi Head office and have had no response from them yet either. I was planning on upgrading my Audi for another Audi but after this debacle and also the poor trade in deal they offered me think I will switch car manufacturers and do not recommend Audi to anyone due to their poor after sales customer service... Pity as when I bought the vehicle I had excellent service but now am left disappointed