it doesn't appear the clamp is forward enough on the post. the way these work, you should be able to loosen the nut, move the clamp forward on the post (you have to pull upwards to move the clamp usually), then tighten the nut, which will angle the saddle upward. but you probably already know that. if it's not working, take the saddle off, try to do this again as described, and see if it can be tightened without the saddle in place. if not, you'll know the clamp is defective in some way. maybe it can be corrected, maybe not.