Air Condition problem:

I have had my '97 Rora, for 3 years. The AC has never worked. Decided to take it to a neighborhood tune-up shop. He got the AC to work, but told me it needed an AC control unit. And he could get one, and install it for $900.00 dollars. After i got home, the AC wouldn't work anymore. So i went on-line and found the AC control unit, for $60.00 dollars, and installed it. Still no AC. So back to the shop. He got the AC to work again. But this time he told me, the AC switch was loose. After i got home, the AC stopped working. I purchased the AC switch, for $14.89 and installed it. But no AC. I am not taking my car, back to that shop. Even though they charged me 180.00 dollars for nothing. I believe i should take my car, to a shop that just works on automobile air-condition systems. Should that be my next course of action.