Had some trouble today to get International calling and roaming facility switched “on” for my China Unicom SIM. Firstly, you need to have the password for your SIM. If you have never set it then you have to send a text message in format of L#AAAAAAXBBBBBB to 10010 where AAAAAA is your default password and BBBBBB is your new six digit password singulair medication. The problem was that China Unicom helpline said the AAAAAA is last 6 digits of your phone number by default if you never set a password. That didn’t work! so had to ask help from a friend who found, by browsing Internet, that it can also be 123456 or 111111. Well, 111111 worked for me and I could set a new password which is then required to be provided to an automated service while customer service makes the changes on your SIM card plan.
Voila. Just noting down to help someone else.