Sounds like it most likely denied due to lack of cooperation… it is part of your contract to cooperate and provide what the are asking of you and if you fail to do so then they can deny your claim. They should have sent you a reservation of rights letter that explains that and gives you a date these documents would have needed ro be provided. You can see if you are able to obtain the documents and send them to your insurance company to see if you can appeal the decision. Most everything is digital there should be records even if it’s prepaid. But you will have to put in the leg work. Also they likely are asking for the auto on stuff because in fire claims more often then not it’s because it’s a mechanical issue and most insurance policies don’t cover mechanical failure so they would need to rule that out.