try hard resetting it
Turn off your device. (Sometimes you have to remove the battery and reinsert it before this procedure, if the device has a removable battery.)
Press Volume UP + POWER ON the device.
Keep pressing both key until the Android recovery menu appear.
Now select from the following options.
Highlight wipe data/factory reset with Volume key (power to confirm).
Now highlight Yes -- delete all data and press power to confirm.
After done select reboot system now.
All data will be deleted!