Dial `##002#` and press call
Dial `##21#` and press call to cancel unconditional call forwarding
Dial `##61#` and press call to cancel no-answer call forwarding
Dial `##62#` and press call to cancel unreachable call forwarding
Dial `##67#` and press call to cancel busy call forwarding
Open your phone’s Call Settings
Go to Call Forwarding
Turn off all forwarding options
Restart your phone if forwarding still remains active