BMW South Africa
Car damaged when was towed by BMW on call

My car was towed by BMW on call on the 22 January 2013 from Mogwase to Rustenburg,
The towing guy check it and give me checklist but when i go and fetch my car it has scratch and the widscreen has chip on it,
The Bmw says its not their responsibility but the car is still on motor plan and the towing person was organised by BMW on Call.