Warranty Rejected on Bogus Grounds

I recently sent my Sony m5 in for warranty testing as the phone kept on shutting off and I would only be able to turn it back on if I plugged it in to charge. This would happen even if my battery was full. <br> <br> I know this is a legitimate claim as Sony has admitted to this being a manufacturing fault here: [URL Removed]<br> <br> Yet, when I sent my phone in it was returned and it was cited that the fault was a result of \excessive wear and tear\". The evidence for this was a slight scuff mark on the top corner of my phone which is most likely the result of slipping my phone cover on as it clips on at that exact point.<br> <br> I have had endless issues with Mtn. As soon as this contract is over I will cancel my contract and never use Mtn again. I will also tell EVERY single person I know never to open a contract with Mtn. "