Complain of rejected claim

I’m am really disappointed in one plan ,they are all nice and convincing when they want you to join .but when you want to claim it’s another story ,you call and call claims department but they will tell you your call will be transferred and they hang up.They do not display professionalism at all ,My Claim was rejected not based on the accident or any fault regarding the accident. They requested that I send them the vehicle documents that I signed from the dealer as part of the investigation regarding my claim ,I asked myself what does the contract had to do with the claim ?that is between me and the dealer .I sent it and two days later they sent me an email rejecting my claim saying the mileage in the contract is not corresponding with the one that I provided when I joined the insurance company why was the contract not asked when I joined the insurance if that is their process ?yes the was a mistake in the contract that the dealer made ,but next to it (the incorrect mileage the is a signature to acknowledge the mistake made )it’s in black and white but when declining my claim they ddnt see that ? Had they asked for my contract when I joined they would have seen the so called “irregularities in the mileage “as they say in their rejection letter .The contract that was sent to me has nothing that’s says when you claim the contract of the vehicle should be provided ,why now ? Because they don’t want to pay my claim ? .Is this what you do to everyone? You portray a good image when you want people to join knowing exactly that when something happens you won’t pay the claim ? Why was the dealer not contacted regarding the mileage? How was it my fault ? Was I the one who made that contract?did I sell myself a car and made a contract ?the mistake was made by the dealer and I have nothing to do with it and it was acknowledged on the contract and you decided to ignore that .??♂️Had you contacted the dealer they would have told you what happened and provided you with the proof or supporting document .I was treated unfairly and my claim should be paid .They are ******