Air Coinditioning Advice Please

I need to have my air conditioning in my Vauxhall Vectra attended to. I am told that something has happened to one of the pipe or summit. Can these be repaired ? How long will any gas remain in the system because some talked about having it just topped up. How long will that last and is it worth it. A workman said it would cot bout £200 to replace or repair that pipes. Is that what usually happens. He also said Vectras were notorious for these pipes being damaged. Any advice / suggestions most welcome