I guess people don't read forums until after they have withdrawal problems with Gox. Seriously, this has been going on since before summer and now it's Christmas. When I had Gox withdrawal issues in July-August they were still answering support emails pretty quickly (just that the answers were pointless) and when I asked to cancel the withdrawal they complied within minutes.
That's your best bet at this point, ask for a cancellation short and firm in 1 sentence if you can. If no reply comes just keep on sending the request until someone gets tired of you. Then take a loss by buying BTC and moving it to another exchange. Seriously, it's easier to get fiat out of any other exchange than Gox. At this point in time you're actually lucky that exchanges like Stamp are pretty close to Gox price all things considered. When I moved in July I wasn't so lucky (not to mention I managed to sell 30 BTC at the lowest point of the dip in July)
Many many thanks for tip about cancellation. For some reason, they replied to that support request in a day, when they hadn't replied to the original request in 10 days.
Guess they know how to respond to cancellation requests. They don't like people moaning about withdrawal times.
They did also mention the 5% "premium withdrawal fee" option. I politely declined
Looks like I'll be getting my money back after all, not have it stuck in a black hole for six months, phew!!