This method can only be used a few hours after server maintence/downtime.
So, open a GM ticket and say that there was a rollback when servers were back up. Tell them that you've been making an X amount of gold the last hour and you lost it all. Be really polite, and have a few friends do the same thing. If it doesn't work when you're doing it the first time, probably they will start to be a little bit anxious and give you the gold. Might work with other stuff that gold too. But I actually haven't tested this.
Try it.