1 Find "Voice call"
Press Apps.
Press Phone.
Press the Menu key.
Press Call settings.
Press Call forwarding.
Press Voice call.
2 Cancel all diverts
After a moment the current settings are displayed.

Press one of the following options:
Always forward
Always forward
Forward when busy
Forward when unanswered
Forward when unreachable
Press Disable.
Repeat until all diverts have been cancelled.
Repeat until all diverts have been cancelled.
3 Exit
Press the Home key to return to standby mode.