faulty car and poor service at the dealer

I took my car at autovaal dealer on 23 august 2015 for service and repair which cost me R 12 204.56. I was told that the car had misfiring and drive train. <br> On the 25 November I received the car and they told me its very good now and parts they replaced there have a guarantee of two years. On the 30 Nov 2015 I saw oil on my floor leaking wen I opened d bonnet I was shocked,I saw lot of oil leaking from engine n wen I called them they told me to bring the car on my way to them I stacked and the car displayed a warning light of drive train again but when I took d car I was told d car was fit n well fixed. They towed it to their work shop. It is disgusting to know that one buy such an expensive car n only to get such a disastrous service. I have given them enough time to fix d car but they didn't. I don't c y it wasn't done thoroughly in d first place. I pay so much money every month for that car and I use so much money as well for maxi taxi to go to work and at d end we pay for a car that spend more time in d workshop than on d road. So to summarise d service n diagnosis of the problem was d 4 inaccurate. These guys are ******* this car was my last I purchase from BMW.