Yep, sounds like you have some faulty equipment there. Could be the riser, could be the sight base, according to where the level is located, it could be the machining for the level itself being off. If you have a torpedo level (short level) take the sight off your bow, stand the torpedo level up straight and plumb, put the base of the sight square up against it and see if that sight level reads level. If not it is your sight, if so then it is your riser machined badly. If it is the riser, then shims like Mercy stated can be used, if it is the sight itself, then take it back and get a new one.