Poor service delivery

I bought a brand new BMW 520i in 2012 and thought that I bought reliability and comfort with customer service. Unfortunately I bought the biggest piece of ******* in the world. The vehicle has been in for repairs more than it has been in for service. About halve the engine has been replaced. I got it back today after it's been in for almost a week due to an oil leak that could be seen from the moon. The oil pump and housing was replaced. This afternoon I drove back home only to get a warning alarm for engine coolant. How in the world do you repair a vehicle and don't check that the rest of the vehicle is in order. I thought it was only Leo Haese that had poor service but now it seems like all BMW service centers are either *********** or ********. BMW South Africa please assist me, take the vehicle, pay the outstanding balance on the financing and rid me of this never ending nightmare. I had to buy another vehicle because I never know when and where this car is going to break down.