Have done the sign up for 1 month, seems to log in via VPN, but don't know how to check leh!
you can try to check using this: http://whatismyipaddress.com/If it still says SG, or no services detected, then most likely not working. This is free! https://www.tunnelbear.com/I set up a VPN on my own router at home, and connect to it while I'm in China. Free and no additional apps needed. But you need to set up the VPN and configure on your phone.
I tink a paid VPN service is more trustworthy. There are lotsa free vpn that are banned in china.
I have checked with my HK frens who frequent china for work. They are using this 天涯 and cost is $20/mth. http://www.tianyavpn.com.cn/