Here are some tips:
1) If you are on a 10-digit local dialing, try entering the leading 1 + number.
2) Try entering the first 9 digits of the 10-digit number.

3) Try entering the first 8 digits of the 10-digit number.
Note: This happens because some central office switches handle outbound calls differently so the call blocker is not able to block the dialing out of numbers after certain numbers have been dialed out. .