"Dun & Bradstreet has already called numerous times. He was told: "We don't provide details about any client to anybody unless they have been authorised by that client as a 'contact person'. Please send all your requests in writing. Thank you for calling."
Hopefully he will soon learn to expect this response, and not bother calling in the first place. I wonder how much the taxpayers of Australia are paying D&B to waste our time and space."