Are they affiliated with the Good Neighbor progrma Disney has? I know there is a whole section devoted to fixing issues with the hotels Disney calls good neighbors, that’s what FIL works in. If they are affiliated with Disney like that, you can call Disney and see if there is anything that can be done. If not, check into the fine print, a lot of companies these days will tell you they have the right to refuse/change things in event of a pricing error, gets them out of legal trouble if they do make an error. I’d still keep going up the chain and see what you can have done, if I remember correctly, you did call and double check that they’d honor that price, so it’s their fault.