the bug

when i go in  to customize my character it freezes and when i wait it still stays there and i cant go back a when i close minecraft and get back on to go back on the world it gets deleted and my friend had it happen twice to him too but he didnt know how to report a bug MY FRIEND WANTS HIS WORLD BACK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!   contact my friend on xbox live the name is NRG J3LL0