i have to admit that my Janome dealer has me spoiled. i haven't waited more than a week for anything - not even when i turned in 3 machines at once.
still, the general impression i've gotten from reading posts here at the board is that a two-week wait isn't out of the ordinary. so that would be my beginning point.
second, i don't think the dealer would take back the new machine for anything other than a warranty issue. even in cases of warranty issues, they won't normally take it back and refund the $$$. if all attempts to fix whatever is wrong fail, they will only exchange it.
none of that means i wouldn't be irritated if i was in your shoes. i just thought you should know it wasn't likely that returning the new machine is an option.