This is a problem that I had a while ago. The president of the company, no less, was getting faxes from some sort of broadcast fax system on his DID number. It was calling him 10-20 times a day, filling up his voice mail and otherwise aggravating him. The only solution we could come up with was to have him transfer the call to an analog station on the phone system set up with a fax machine. That was the fax was answered, and we had the name of the people who were broadcasting to his extension. We contacted him and he was removed. It was the only thing that worked. Hope this helps.