If you do so choose to tell off the pilot because he lied, just be sure and do it before takeoff. Preferably it should involve your being out of your seat during taxi while the FA's are buckled in. That way when you are pounding on the cockpit door shouting profanities and calling him out of his little protected box to confront you like a man, it will take some time for anyone to be able to get to you and pilotely ask you to reseat yourself.