Please turn off the device then press Volume Up + Power Button. Keep these pressed until the Android logo appears. Use Volume Up/Down to select Wipe Data/Factory reset then reboot the device.
If you have registered the device you can go onto Samsung locate me and sign in using your Samsung login details which allows you to unlock
the screen. Hope this helps :)
problem solved, good suggestion on your site.
I have the same situation here going on now because I am really panicking for what I have done plus when ever I was adding all my Gmail accounts it was just not letting me and also the pin which I...
turn on your device then press the power button once then you device will show like this:
data network mode
data network mode deactivated