Sad to know about your experience, it seems you'd not sufficient knowledge of these cars and their models while buying nor you did detailed research before buying. There're many helpful posts that every buyer should must read before buying the ride.
Chevy Exclusive is the korean assembled 800cc car that comes in two different models i.e. Exclusive Standard and Exclusive LS. Exclusive Standard is the simple and standard exclusive whereas LS has something additional like power steering and front power windows. Also i think standard exclusive originally came with black bumpers whereas LS came with matching bumpers. Have a look to your car's documents and confirm the exact model name. It should have power windows and steering if it's Exclusive LS.
Also these are old models now so there're fewer chances of getting ride with smooth power steering like new cars. Mine is also 2004 model and it's power steering isn't as much soft as new cars have.
I could guide you about AC expert if you reside in Rawalpindi/Islamabad, no idea about lahore but I'm sure there would be many posts here regarding AC Expert in Lahore.
You're welcome to ask if you need any more info