House fire

We had a house fire due to a faulty fire place and no fault of our own. Insurance company worked with us to repair and replace house back to livable condition. We are now in a final settlement dispute over contents replacement and total loss recovery and time of claim is one year which will be up in three weeks. The adjustor sent us an initial offer which is way lower than what we had submitted for claim. We have sent a informal letter to adjustor on our counter-offer and had not heard from him in three weeks. what would be our next step? Would we send a legalized demand letter and where do we get one?