Stanmar motors, Mercedes

Our Mercedes has been to all its services in the motor plan. The first one out of the motor plan was going to costs R32 000. When i quiried that, head office informed me that it was a faulty diagnosis. I am waiting two weeks already for any body to contact me and discuss what i need to service and what the way forward is. Previously i went to Stanmar motors to get my reverse light fixed, i had to go back 4 times for the same thing before it was fixed correctly. Very bad service and no communication from such a well known, supposedly upmarket car dealership. False promises were also made by the sales person when we bought the car. He said we will receive a car to drive everytime the car is in for a service....never happened. No car ever available, even if we book weeks in advance.