Air con not working

[Kevin37]

So I've taken my car to quick fit and had it re-gassed but the air con still blows warm and no where near as cold as I'd like.

The guy in quick fit wasn't able to tell me what was wrong. But after a quick google I think it's either the switch or the compressor.

What I want to know is,

Is there any way of telling what's at fault, either by visual inspection or vag-com?

I know it's not the gas, so does that mean it's going to be an expensive fix? The compressors are silly money by the looks of it and knowing my luck with car it will be the most expensive part that's gone

[h45gti]

checked for any leaks? or hissing noises? mine was hissing from the pressure switch just under the electrical bit, bought a new switch but trying to get hold of a crowfoot spanner to unscrew it, will post if it fixes it, may also need the rubber seal too :/