Whether or not you have a legal basis to bring an action against your lender for false information for the loan that you ended up receiving would have to be based upon a detailed legal analysis by a real estate attorney after he or she has reviewed all of your loan documentation.However, from what you have written, there seems to be a factual basis for contacting a representative for your lender to see if the lender would be willing to re-write the terms of your loan into a fixed rate situation.