Talk to the LBS where you bought it and explain what you don't like about the current fit. You can swap stems, bars, seatposts, etc. if you need something that is a bit beyond the available range of adjustment. I modified a rigid MTB to make a fitness/cruiser for my wife. She also likes a more upright riding position so here is a list of what I did:

- Shorter stem with a few degrees more rise
- Handlebar with about an inch and a half rise and a few degrees of sweep
- Moved seat a cm or so forward
- Changed to a women specific comfort seat (at her insistence against my advice)
- 1.5" semi-slick road and trail tires

Whenever you make changes, give yourself some time to adapt before deciding if you likes something or not. Sometimes things feel strange just because they are different and your body takes a while to get used to it.

+1 on NOT getting a "comfort" bike