Before I purchased Lumia 521 through WM, I thought I can make free Wi-Fi calling using this phone. It appears it is not the case. I also try to use skype voice, it appears it is not the option as well. My questions: (1) If I unlock the phone, can I still do free wi-fi calling? (2) Has anyone used Lumia 521 to make voice call through Skype? (I did that with my old Nokia C6 and has no problem making voice calls through Skype).