BMW JSN ALWAYS gives terrible service!!!

When I booked my car in for my lights that weren't working Elsia told me that it would take a few days. He then took a couple of days to inform me that the problem is with my control unit. Mind u I had taken my car in two months before for the same problem but they didn't pick up that the problem was the control unit.A week went by and there was still no proper update. Two weeks later they send me a invoice of R9000 at 15:30 and I pay it immediately, the secretary calls me at 16:00 to tell me my car is ready for collection. When I arrive they refuse to give me my car because the money hasn't reflected, when I had already sent Elsia and Robyn my proof of payment, I begged her as I've started at my new job & having serious transport problems w/o my car. What is the point of a proof of p. Elsia during the whole time was very unprofessional as well as Robyn. Every single time I take my car for service there (cos it's the closest from where I live) there's a problem EVERYTIME!!!! Sick & tired of this ****. They have completely put me off the BMW brand & will never buy another one. Totally disgusting!! I suggest you go 2 another BMW dealership to get your car serviced.