We bought the same one, and it wasn't straightforward. So ignore the poster commenting on needing a handyman. How ridiculously pious and unhelpful.
My partner is very handy, and it still took him two hours. Not sure four hours was necessary, and frankly, complaining about missing parts sounds like something my father (who is NOT handy) would do. Afraid you might have been ripped off just a bit...
But the good news is YOU didn't have to do it!!