If the phone won't turn off by when you press the power button and volume up key simutaniously, try the following:
1. Check if the button is faulty.
2. Check if the phone has crash dump or freeze issue. Press and hold the power button for more than 12 seconds to force the phone to restart.
4. Uninstall and remove any recently downloaded apps.
5. Back up your data and restore your phone to factory settings.
If the issue persists, please contact our Customer Support for further assistance.