Hi @Iso_Ly, sorry to hear the issue. you may try to factory reset the phone by following this method:
Please note resetting the phone will erase all of your personal data from internal phone storage, including your accounts, phone book, downloaded application, setting etc except for data stored on SD card, so please back up your data before factory reset. There are 2 ways to reset your phone.
in power on state:
Click Settings -> Backup and reset -> Factory data reset -> RESET PHONE.
in power off state,
1) Long press “power” key and “volume up” key to enter the boot mode interface.
2) Press “Volume Up” key to select “recovery mode”, press “Volume Down” key to confirm.
3) When see green robot logo, press Power Key and Volume Up Key together twice to enter recovery mode.
4) Press volume down key to select Wipe data/ factory reset
5) Press volume down key to select " Yes---delete all user data".
Warning: this action will erase all your personal information and downloaded apps.