If it was working properly BEFORE you had the body work done and now its not working AFTER, then perhaps they are at fault.
Open the hood. Start your car. Turn on the A/C. You should hear a CLICK. Look at the front of the compressor, where the belt is. That's the clutch. If it's not spinning, then the low pressure cutoff switch has engaged, protecting your compressor. Thus, your system pressure is very low.
If the clutch plate is spinning, then there's enough refrigerant to keep the cutoff open. Stick a small dial thermometer in your dash vent for 5 min. and note the temp. It should be at least 50 F, unless it's less than 75 F outside. If it's close to ambient or hot, then it's either your A/C system OR if you have auto-climate control, the control unit may be toes up as it's mixing hot air into the cold air when it's not called for.
Given that your vehicle is an 03 you could have a slow leak somewhere. Find your HI & LOW pressure service ports. (You may only have one). It'll have a plastic cap that unscrews. Listen for a pssssst when you unscrew it. It means that the Schraeder valve in the port is leaking.
If your system has dye in it, use a black light bulb from the HW store in a dark garage to look for the glowing leak.
Good luck!
