Urgent Assistance Required

I submitted a claim for portable possessions which was authorized however approval was based on the currently selling price of the item whereby the item is insured for way more almost three years ago - to make sure that the item was not under insured in an event of a claim. I am not happy about the settlement and request an urgent review. I would either request a full settlement based on the sum insured where may premium was calculated accordingly, Or the insurer refunds the difference in premium to me based on the settlement amount offered.