depends what model & engine you have.
1.8L engine is 24/29 mpg, average 26
2.4 engine is 23/28 mpg, average 25
2.4 AWD is 20/24, average 22
Sounds like your car is performing just about at EPA estimates for city driving, so really you have no legal complaints. If the dealer lied to you and told you 30 mpg, and if that is not advertised or in writing, no one is going to confess to the AG. You can't expect a car to exceed EPA estimates.
Give it a good higway run and pay attention to which engine and drivetrain you have. The numbers I posted are realistic ones.
If you have the small engine and 2WD, and you don't get close to 29 mpg on the highway, you can complain to the dealer about that.