Car Dealer Dishonesty?

I bought a Pontiac Grand Prix 06 about a month ago. At first I thought this car was better than other ones. After an inspection, i spent $600 fixing minor transmission oil leak, tire suspension, windshield wiper leak, and battery. After all these, I found out that the car doesn't even have a keyless entry after been told that a fake keyless remote just needed to replace the battery. (i'm currently at college, didn't have time to check this out in the first place, then i went to different shops to check the reason why it's not working). What should I do?