BMW Alberante shocking service

<p>Took my car in because the cool ant low warning light would come on and water finish within a day. BMW diagnosed the car and said thermostat and water pump must be replaced and charged me R12000, i pay and they fix the car. I collect the car and following day the warning light comes on again, I call them and they say I must bring car back. I have returned the car and now they claim the radiator is leaking and I must pay another R10000 to fix it. My question is why didn't they pick up the radiator problem before and why tell me to Change thermostat if the radiator is the problem. I called and asked to speak to the service manager and he said he will investigate and call me back. He never did. Just sent someone to tell me to pay for the radiator. Its actually day light *******, I must pay twice to fix the same problem.</p>