Have you tried this:
Power Device Off First.....
1. Hold Home Button and press power
2. Screen will show a Android with a triangle with astrick
3. Let Go of Home Button and Power
4. Press Search Button (Far Left Button)
5. A blue menu will show at top of page, scroll to Format Device
6. Select Yes to verify
7. Allow format to complete (Information at bottom of page will go through a few steps)
8. Once Format is complete Blue Menu will show at top again, select Reboot
Note: Use volume up and down to select opinion and use camera button as Enter,,,