Disappointed with the service

I'm very disappointed with Joburg city auto this is my second experience were I took my car in for service and i was told that the car radiator has a stone chip with them don't cover, my aircon was not working due to that, by then my car wash still under motor plan, I claimed from my insurance and was advised that there's nothing wrong with the radiator they tried regasing only to find that the compressor is the one with the problem, I laid a complain with BMW south Africa it's over a week now and no one got back to me, the saddest think its that my my car is no longer under motor plan, this is not the first time I experience such service from Joburg auto.I've been a loyal BMW for years but I am extremely disappointed.I need someone to get to the bottom of this, I don't understand why Joburg auto couldn't pick up the problem.