Clueless technicians

THE WORST EXPERIENCE. Took my car to BMW Dalpark to get it checked for a leaking coolant, mind you this was before the scheduled annual service - and I was told there was nothing wrong with the coolant system all is fine. A day later I had my service done and a vehicle check done, the vehicle hadn't even travelled 200km, the coolant light came on again, we filled up and in the process the bleed ***** broke and we replaced it, the coolant light still came on and I went back and disclosed that I still have the issue however I replaced the speed ***** myself. They said perhaps it was the bleed ***** and everything is fine. I believed that given how easily it broke. Travelled about 300km from Gauteng to Cape Town, Coolant light came on again and the engine was heating up. I am so frustrated. I don't know how many times I told them about this. What does a vehicle check mean to them? When I tell you there's an issue, you can't say there's no issue just because you can't find it. Be better. Look harder.