How do you block the scammers that use an extra digit in their phone number?
When you attempt to add the number to the Incoming Call Block you get:
Please enter a valid phone number.
I am guessing there is no way to block.
You are correct and that's why scammers add that 11th digit. If you have FiOS you should be able to block it through the features portion of your account page. I have had luck doing that with mine.