2.5 year iPad not covered due to so called 'wear and tear'

The screen of my son's iPad stopped working. It is 2.5 years old. I sent the claim in to Discovery and a company came to collect the iPad. I was told that the repair would not be covered as the damaged caused was due to wear and tear. Discovery's definition of wear and tear is 'gradual deterioration or operating causes such as rust, mildew, insects, corrosion, rising damp or decay'. I do not accept the rejection of my claim as the iPad isn't even 3 years old. The life span of an iPad is 3-5 years. This claim was placed on 25 Nov and I was told on the 9th of December that it was rejected. Since then no one has even phoned me to tell me where my son's iPad is! So not only have Discovery rejected my claim due to unfair reasons but they have also ****** from us!