That sure looks like one incredibly big ugly improper gap. In my limited experience a nasty enough one to make me wonder if it was attached properly and profesionally at all.
If you haven't accepted delivery, don't. Get the surveyor, insist that Jeanneau have someone down to inspect the boat (and present their conclusion in writing) and if someone doesn't pull a rabbit out of the hat, you may need an attorney. Not just to get your deposit back, but to avoid being sued for refusing delivery. It might be worth contacting Jeanneau headquarters as well, and telling them there's something very odd happening over here.
It is hard to tell from that picture, but it sure does look nasty.