The Unitel Voice virtual phone system allows you to block numbers and entire area codes from calling your numbers. Also, you can create a list of specific numbers that are exempt from call blocking.
Call Block is found under "Settings" > "Call Block"
Blocked Callers - Enter the ten-digit phone number that you would like to block, and click "Add."
Blocked Area Codes - Enter the three-digit area code and click "Add."
Numbers Excluded from Blocked Calls -Enter the ten-digit phone number that you would like to exclude from blocking, and click "Add."
Adding numbers will build a list. You can easily remove numbers or area codes from the list by selecting the "X" next to the number(s) you would like to remove.