Bad service and attituted from dealer

I took my car (Audi TT 2007) for a service and a cambelt replacement. I was phoned on Wednesday the 12th and was told that the 1 engine mounting was broken. I asked him to replace it, the costs was R3000 ekstra. Friday the 13th I phoned again to ask how far my vehicle was. They told me I can have it on Monday. I collected the car on Monday morning and had to pay R19115.00. After collecting the car I took it back because the vehicle didn't have any power.I was phoned 3 times and told that I must come and collect my car the next day because they are not going to fix the car because I refused to pay any more money. According to them there is a switch broken and will cost another R10000. There was nothing wrong with this car when it went in for its service.