Dishonest car dealership for car diagnosis

I am writing to express my dissatisfaction of the service I received from BMW /Mini Dearlership in Sandton. Recently, I took my Mini Cooper to their dealership as my car couldn't start and a tow car driver helped me to jump start the car and have it towed to this dealership for diagnosis and repair. They are very quick in sending me a quote to have the battery, thermostat housing and coolant pipe changed at a very high cost. As this car is out of motor plan, I cannot afford to accept the quote and hence declined the quote and requested to take out my car to have the car checked elsewhere. I was charged R1,600 for one hour labour for diagnosis which I settled immediately and took my car to another garage. I was told that the battery needed to be replaced but there is nothing wrong with the thermostat housing and coolant pipe. I feel deceived by BMW Sandton's misdiagnosis and their inflated charges. It is unacceptable that a reputable dealership would take advantage of a customer in this manner.

I believe honesty is essential in maintaining consumer trust.