Slide your finger down the display starting from the top edge of your mobile phone.
Tap Settings.

Tap Call settings.

Tap Call forwarding.

After a moment the current settings are displayed.

Tap each of the following options:
Always forward

Forward when busy

Forward when unanswered

Forward when unreachable

Tap Disable.
Repeat until all diverts have been turned off.

Tap the home icon to return to the home screen.