Hello. Do a master hard reset using the hardware keys.
1. Turn off the device.
3. Press and hold the Volume Up key and the Home key, then press and hold the Power key.
4. When the Samsung GALAXY Core Prime logo screen displays, release only the Power key
5. When the Android logo displays, release the Volume Up and the Home key ('Installing system update' will show for about 30 - 60 seconds before showing the Android system recovery menu options).
6. Press the Volume down key several times key to highlight 'wipe data / factory reset.'
7. Press Power button to select.
Press the Volume down key until 'Yes -- delete all user data' is highlighted.
Press Power button to select and start the master reset.
8. When the master reset is complete, 'Reboot system now' is highlighted.
9. Press the Power key to restart the device.