Blocking Calls from a Specific Number:

  1. While viewing the home screen, press "Menu"
  2. Tap "System settings" > "Call"
  3. Tap "Call reject" under "Other call settings"
  4. Tap "Call reject mode" if necessary, and tap "Reject calls on list"
  5. Touch "Rejection list" and press the "Add" icon
  6. Perform one of the following:
    • To block a contact, select the desired contact and tap "Done"
    • To block a number from the call logs, choose a call log entry and tap "Done"
    • To block a phone number, type in the number and tap "Save"

Unblocking a Number:

  1. Press the "Menu" button while on a home screen
  2. Tap "System settings"
  3. Tap "Call" > "Call reject" > "Rejection list"
  4. Tap the icon depicting a "Trash can"
  5. Choose the phone number(s) that you wish to unblock
  6. Tap "Delete" and press "Yes" to confirm

Blocking Calls through Third Party Applications:

As seen above, the LG Optimus F6 offers a decent amount of call blocking features, but in case these options are not enough for your blocking needs, then you might want to give various third party applications a shot. Apps such as "Call Blocker", "Call Control" and "Call Blacklist" (or similar) offer a wide range of options, including black and whitelists, call logs, the ability to block messages, password protection, notifications and more.

See More: LG Optimus F6: Blocking and Unblocking Calls (via Default Features or Third Party Apps)