Complaint Review: Honda of Joliet

I recently visited a Honda Dealer in Joliet Illinois. I was patient in selecting the car I wished to purchase (2001 Civic).
I was informed by my agent that I would receive:
-$4500 for my used 97 grand am coupe. (I owe $4200 left)
-$4000 for the 4000 miles on the car. (demo model).
-6.5% financing.
-rear spoiler and hood bra no charge.

I now regret my decision, My loan agent informed me that my loan amount was exceeded and asked for me to verify some items listed on car...
-I did not purchase/nor did I get a Premium sound system.
-I did not purchase/nor did I get chromed wheels.
-I was not to be billed for the hood bra or rear spoiler.
-I did not receive $4500 cash back on my used car.
-I did not receive $4000 off the sticker for the demo.

They sold this to me as a NEW car and none of the options I selected. They didn't sell this to me as a DEMO (which it was).

I returned to the dealership after being told by my loan officer not to sign anything. The dealer refused to return my used vehicle..he was extremely rude! I just want my car back and to have this all forgotten, is that to much to ask? I almost broke down and cried and I feel so sick. It's a demo car and they won't even take that back...I thought I was buying a great car in honda..and a reputable company. I am completely lost.

Please help me.
Michele Tahlberg.