Horrible ****mers

Took in my car in at BMW West Rand in July for a Drive in Train notification, and i was told they needed to replace a turbo, and on the report they mentioned it might have been caused by over heating. I paid over R50k for the car to be fixed, and now 6 weeks later the same message appears and they say is the same problem they need to replace the Turbo, and it will cost me over R70K because its caused by over heating and leaking for the coolant. The warranty on the turbo they have put in doesn't cover that. absolutely madness, how am I expected to buy a new turbo after I bought one 6 weeks back it doesn't make sense at all. BMW is *********** and they take advantage of their female customers. I'm so disappointed in them.