If you see that your phones keypad is locked like here on the picture and don’t know why
then most probably haven’t locked the phone yourself or by accident.
The keypad is locked by continuously pressing the * (star) button for 5 seconds.
to unlock the phone please do the following:
press the * (star) button for 5 seconds until you see this menu appearing (picture)
if you accidentally locked the phone there will be no password set so:
Press OK and the phone is unlocked