That's what we wound up doing. We had to accept the call and tell them in person to stop calling. Unfortunately, that's what the Privacy Director is supposed to do - insulate you from having to talk directly to them. You press 2 to reject the call and that should be enough. In the case of Arbitron, they took the reject to mean "maybe; call me later."
Arbitron is officially on my *crap* list.
John