First, how long have you owned the bike? My shop allows a 30-day return period, and they only charge a restocking fee if the bike is noticeably worn. If I were you, I would try to bring it by the shop you got it at, just explain how you feel, that you want to get the same bike or another bike from them (not a refund) just in a better fitting size.

If that's not an option, you can find something relatively cheap. I believe the Ritchey Comp seatpost comes up to 400mm long, and is like ~30.00, with 2cm of setback (which should match your Fuji).