screenshot your site page and inventory?
just to prove you did get robbed.
DId you look into your archive of messages?
When they was stupid enough they didn't delete them and you can see who it has now.
you probably did "skip the fun" if you had ten k left.
are you level 30?
edit: you have to check your "messages" button next to your gold, to see recent transaction messeges. they should be unread or in archive.
Any idea of somebody who could've broken into your account?
Like, you shared it with somebody?