Thanks for the report. We are looking into all these reports regarding the joystick not working and the screen not responding. It has been a bit tough to determine if all these issues are related or different, thus the reason we have not been able to fix it yet.
As some of the other players in the sub have asked, did you happen to open your friend's list? What exactly did you do prior to the issue happening, thats the really important part. If you could let us know and if this happens again please make sure to report the issue while ingame so we can get your game logs.