From the Home screen, select the Dialer icon. Note: The call blocking feature may not affect phone calls made or received via third-party apps installed on your device. Please contact third party app developers for assistance with such applications.
Select the Menu icon.
Select Harassment filter.
Select Settings icon.
Select Numbers blacklist.
Select the Add icon.
Select Desired place to a add contact from.
Select Desired contacts and select the Check icon.
To unblock a number, go to the Blacklist list and select Desired contact.