Declined claim because of incorrect legal interpretation

Submitted a claim for our house sealings which are badly damaged as a result of rain leakage. The Assessor came out & summited the necessary photos & documents to Standard Bank Insurance. To my surprise the claim was rejected because of wear & tear. Wear & tear in my mind is consumer goods constantly being used & wearing out eg...driving your car, using your appliances ect. Can SBSA possibly explain how rain is wear & tear & what I as a customer is supposed to do to prevent the rain from falling on the roof, to prevent the "wear & tear?