There are several ways to block contacts from calling on your LG Optimus phone. One is to ignore the caller. Second is to send the number to voice mail option. You can also apply apps to block calls or SMS. One app is Mr. Number Call Block. Another app is called GBlocker. To check out other free apps to block calls and SMS for your LG Optimus, go to https://market.android.com/search?q=block+calls&c=apps&price=1&so=1.
Go to Settings>Call>scroll to (Other Call Settings)>Call reject>Rejection List. 1.Tap the + on the upper right corner 2. Choose the source of the number you want to reject 3. Tap save-- you are done If you want more numbers in the list repeat step 1