Most likely, personally I wouldn't let Kwik fit do anything other than re gas it, I would take it to a specialist.

When you say will not accept gas, do you mean it was leaking it, as I had the same problem when i regassed mine, I left it though as there isn't really a way to tell where it's leaking from, whereas, professionals pressure test the systems etc and have UV die etc, so the location of the leak can be detected.

It could well be the compressor, but you don't want to hear "Maybe", again a specialist probably has these parts off the shelf so can do an accurate diagnostics and replace it if necessary.

Martin