Unsatisfied Customer Mercedes Benz

I have a recurring problem with my car. It has been to Mercedes Benz centurion countless times for the same problem. And everytime it is there I am charged for something and promised that the problem will not happen again. As I am writing this, I am in the middle of the road on N1 with kids in the car. Where is the safety in that. The car had a tendency of cutting out and switching off whilst driving. It does this in the middle of the road. It is now the 7th time that it is doing this. If one is to check on how much was spent on this car since December 2014 to date (R100k+). It is hardly two weeks since I had it back from the dealership where it spent 2 months. Either it is a sign that never trust a Mercedes when it goes out of motor plan. I love the brand, but the recent misfortunes are actually making me reconsider the brand and also advise other people not to go for it. It is like you are given a temporary fix. At this moment I am not satisfied at all with the service given.