That's the exact response I got too. I asked for the accounts the gold was moved to but support wouldn't supply that info.
He also won't confirm or deny that it's a game bug. The only thing they will do is rollback the account but if you use your restoration now, there's a very good chance you won't be able to do it in the future.
Support can't (and shouldn't) provide you with other account information.
And pick the more likely scenario:
A) There was a specific bug on the servers that only attacked certain accounts, wiping them clean of all their possessions.
B) You got hacked.