Hy. Unfortunately my mobile has just 10 months and has two problems. First the smesh speaker unglu and now the back buttom sttoped to operate. I would like to know if has one authorized service in Brazil? I would like to fix my Mobile because I like it a lot.

Did you do anything on the phone before that started happening? If you already tried restarting the phone and back button still won't work, I highly suggest having your phone checked.