Cartime Gonubie- failed to correctly diagnose my car

I had the worst experience with Cartime Gonubie. I took my old car to them because it was overheating and there was a leak I had noticed. The the water was also finishing way too quickly. The first time they changed the water bottle that was supposedly causing the leak and was the reason the water was finishing quickly. Did it help? Not really. A month down the line, same story. I took it to them again and well it was a new story - the radiator was worn out. They got a new one and was the car sorted? No! About a month down the line again (18 November) I fetch the car, the new radiator has beeb fitted and car should be all good. Two weeks later (28 November) I am driving longish distance out of town and the car overheats again and my top completely blew off. This is after spending about 10k on fixing the car at Cartime without correctly diagnosing the car. I am so disappointed and actually annoyed!