Open the and tap the three dots (Menu) in the top right corner. Go to Settings > Supplementary services . Tap Call barring .
Select the category (e.g., Outgoing calls, International calls) and toggle the bar to . how to remove call barring o2
If you cannot find the menu settings, you can use universal GSM codes to reset barring. Enter these into your phone's dial pad as if making a call: Open the and tap the three dots (Menu)