“Secretary: Just saying “we’re not interested” won’t stop a telemarketer from calling you again a month later. Instead, say “We don’t use [whatever] here”. Not only will this ensure that they remove you from their list, but the caller’s befuddled silence can be quite hilarious if they are are hawking something common and you reply with, say, “sorry, but we have a strict policy against chairs in this office.”
Tricks of the Trade / Professional secrets from those in the know