Samsung Galaxy A3 (2016)
Android 5.1.1
1 Find "Voice call"
Press Phone.
Press MORE.
Press Settings.
Press More settings.
Press Call barring.
Press Voice call.
2 Turn call barring on or off
Press the required barring type.
Key in your barring password and press OK. The default barring password is 0000.
0000
3 Return to the home screen
Press the Home key to return to the home screen.