unlock my blackberry

Last October, I bought BLack berry Z10 from att at college station, TX, it is an unlock version and I used prepaid. Now I am at China, I need wep code when I insert the China mobil SIM card. The IMEI number on the back of the phone is ***, but it is [edited for privacy-please do not post personal or unique information such as but not limited to full names, employee ID numbers, email addresses, phone numbers, account numbers, etc.] when I dial *#06#. Can you help me to get my wep code?
Thank you.