If you are receiving a high volume of calls from private or anonymous numbers where the Caller ID is hidden, you can activate Anonymous Call Rejection. This forces callers with blocked IDs to unmask their number before the call can go through to your house. To activate this feature from your handset, dial *77.
Enter the phone numbers you wish to block in the provided fields and click the plus icon to add them to your list. Ensure you click Save to apply the changes. Activating Global Call Rejection how to block a phone number on a landline spectrum