Two calls from them today on my unlisted landline. I don't answer, they don't leave a message. I know they couldn't care less how utterly infuriating these calls are, but I do - it's like having your doorbell ring every few minutes and finding someone standing there with a clipboard trying to sign you up for magazine subscriptions.
I have been getting calls from this number lately. Three times today for whatever reason. I am on the National Do Not Call Registry for whatever good that does me. If I don't recognize the caller, I don't answer. Does not stop them from calling again and again though.