No Responsibility for Damage they did!!!!!

My sister took my car to Ford Menlyn for them to see what's wrong with the bluetooth button on my steering wheel. The service administrator, Dineo Mbethe opened my cubbyhole and broke my TomTom. She told my sister "sorry I've just cracked the screen of the gps". I've contacted the service manager, Ray, and he told me he will have a look at the security cameras to see what exactly happened. He called me back and deny that it was a mistake on their part. How is it possible to see from a security camera view what happened INSIDE the car??? And they make my sister out for a ****! Well, needless to say, I was very upset!!! They didn't even apologize OR come to an agreement to at least pay half of what it will cost to replace the gps! And to top it off - I have to take my car back to them to fix the button, because they've ordered the part! What will be damaged next?? A scratch or bump on my car??? How is it possible to trust them???? Well never!