Hey boby, I've been looking for almost one hour where was the Farkin form to report stolen account, but wasn't able to clearly recognise it.
There is numerous forms here https://www.battlenet.com.cn/support/webform.xml?locale=zh_CN&selection=WorldOfWarcraft
and the right one might be 战网-------账号修复/密保解除(battlenet----account repair/password recovery or something like that). You'll have to complete the form and send a scan of the ID card you used for the account.
Try to ask a chinese friend to give you an hand. You could also try to call the 021-6162 6168 and ask them how to recover your account.
Sorry I really would help you with this if my chinese was better but I'm really at the same state than you, so google translate and chinese friend are your best friends.