My brand new green bike had the same seat latch issue as the OP since day 1. It was a matter of simply straightening the curved latch a little. And yes, the latch is curved, for some reason. Resist the temptation to straighten it because you'd go way too far. Also DO NOT try to straighten it while installed on the seat. You could break or crack the plastic. Put the latch on a vise, bend it a little, reinstall, and try until it's just right. Use a flashlight so you can see how much clearance you need. Keep in mind you'll have to push the seat forward enough for the bracket to drop into the latch mechanism, then push down on the seat a little until you hear the click. Mine latches perfectly now, and solid as a rock. I would never use a dealer for that kind of thing, but to each his own. If you do, check everything and make sure nothing was cracked or damaged (it happens). Good luck.