All fixed! :banana:
Got a call from Chatswood this morning saying the window had arrived quicker than expected and that I should drop my Tig around. I did so and collected it this afternoon. The guys there were very friendly and polite, and I'm very happy it's been resolved.
Having a chat with them they said they'd like to this this sort of problem is one-off, but they couldn't assure me it wouldn't happen again. They said it's good I kicked up a stink as they keep telling the regional manager about nil-stock problems, so maybe the customer doing it will yield more fruitful results. I hope so too.
Thanks Chatswood Classic for all your assistance and helpfulness, and for VW Aus responding to my complaints.