Bavarian Motor Waste

My BMW 320d has been in Sandton Auto for the past two weeks. Prior to that its been in and out for the past 4 months since its last service. There are a whole lot of warning lights that keeps coming on and it even stalled once on the free way, I have been in touch with the Principle dealer of Auto Umhlanga were I bought the car from, Sandton Auto who are fixing it but are clearly not doing it well and BMW SA. No one is taking accountability or making a decision on what to do with the car as I have asked for a replacement. It is utterly disgusting that BMW can provide this type of service. I will be contacting my bank and will be taking legal action against BMW if this cannot be sorted out by this week as I've been having this problem for that past 6 months and the isn't even 2 yrs. I have lost all confidence in BMW.