Misdiagnosis and poor service BMW menlyn auto

I took my car to BMW menlyn auto 2weeks ago. They called me to tell me they ordered some parts and fuel pressure sensor pump. 3days down the line they said they installed an incorrect part and they have to take it out and order another new one from BMW sa. 2days after that they told me my car bombed out and they are still busy reprogramming it. This monday i was called 2collect my car. They charged me 7k and told me ive got 24months warranty. I drove 3km and on my way to work from the dealership my car stopped and there was oil all over the pavement. I called them and they came over to tow away my car back to the dealership. An hour later they called giving me a new quotation of R25k and said that theres 4things faulty with my car. One of them was oil leak. Which was not diagnosed 2weeks ago when they took it to the workshop. These people kept my car for 2weeks,diagnosed it and gave me a quote,claimed that the car was fixed and on the day i collect my car i did not even drive it 3km and i got stuck. Day light *******.- DrLekota