Integrisure trying not to pay claim

Vehicle was ****** Dec 20th 2014.. Vehicle has now been assessed. Assessor says its a write off.. Integrisure now are trying to say that insured benifactor has no paperwork.. However it has been explanned that the name on policy is a partnership between two individuals with a company name at the bank.. nowhere was it stated that the name was a CC or a Pty. Now they say they need legal documents proving that.. however they have received from me a letter from the bank showing it is a partnership bank account with a name.. Now they want to refuse claim payout on that basis..