I don't know if "screwed" is the right word but I for one would not be happy. I would call Excel Industries and give them the serial number. Ask them if if there are any changes for units produced in July 2014 vs. a unit made in say, February 2015.
Either way, I'd be asking questions and requesting some money back. IMO...you got a leftover new unit....not a current model year unit.
Jeez....especially on a a Super Z (high end Hustler) purchase....and from a dealer?