Another idea is if there are any Public Adjusters (represents the property owner as opposed to the Insurer) out there, they may be able to assist in the formal process against the Insurance companies. This is what they do for a living. PA’s (as they’re called) typically get involved at the beginning of the precess. Many people don’t know they exist. Most PA’s will work for a % of the $ amount received from the insurance company.
Here is a link to the National Association of Public Insurance Adjusters – http://www.napia.com/
Just a thought and hope it helps.