First off, you shouldn't have proceeded without first getting Nationwide to approve it. Real simple there. Now, you can have the HO call, explain the situation and ask for it to be reconciled. She should tell them the contractor is billing for 52 squares, they have to pay it so Nationwide needs to pay them. If the adjuster refuses, the HO must demand to speak with the Adjuster's manager. If none of that works, you can go to appraisal or have the HO seek an attorney. Be sure to file a complaint, with the proper documentation, with the Director of the State's Department of Insurance.