It's exactly the same situation with the Telephone Preference Service in the UK in my experience. The only way I've managed to get these calls to stop is to get

It's exactly the same situation with the Telephone Preference Service in the UK in my experience. The only way I've managed to get these calls to stop is to get withheld numbers (ie callers with no or blocked Call ID) blocked at the phone company level - which usually incurs a monthly fee, of course...