Unfair rejected claim with bad service

I drove through a water patch and my car had started to go into lym mode and I had the car towed to Audi after the diagnosistic they told me the water had damaged a component in the car. I reported this to Hollard and after that I had to keep calling Hollard as not once did Robert contact me or return my calls he was always unavailable. Eventually the assessor went out to see the car and confirmed the water damage. They decide to hold it back and send another assessor to Audi. The assessor went after to go see the car and disappeared and then went back again to take photos. Still not once did they contact me. After calling them they tell me Audi must confirm the water damage. Audi service manger emailed them saying as per my discussion they checked car and showed the assessor the water marks in the plugs and he took photo.Then Roberts calls me and tells me that I told the assessors where the water marks are which is a LIE as I never met the assessors at all neither can I show him a part under the vehicle. Then Roberts calls me and tells me my claim is rejected as car has mechanical damage. They have rejected my claim with no valid reason and have not proved it was not water