Awful Service from Discovery Insure

Firstly would like to express how deeply disappointed I am with the service that I have received with my claim through Discovery Insure. The lack of disregard that they have for their clients is shocking. I submitted an appeal letter after they rejected my car insurance claim, it has been over 3 weeks and I have yet to get a response or any communication from them. I believe that they are purposefully ignoring my emails so that appeal period lapses. They way that they have handled my claim has been shady from the start, whilst my car was in their possession they removed my cars license disc and put auction stickers before they had given me the outcome of my claim and for me to decided what my options were. Which shows that had no intent of fixing my car from the start. They initially agreed that my car had been written off due water damage and that they would be paying it off. But when the time came to pay the money due to me they changed their tune and refused to pay and stated that they were rejecting my claim which contradicted the initial outcome of the claim. I just want them to respond to my appeal letter so that we can put this matter to rest. Im really not happy with the way that they treat people after receiving my monthly premiums for years. They should be really ashamed of their service.