I would tell him I'm signed up to the Telephone Preference service and that I would be reporting him for cold calling me.
Actually, if he phoned me up at 6am (apparently he made one of his first calls at this hour, presumably because he's so divorced from the real world, he doesn't realise that most people don't like to be disturbed at that time in the morning), all he would receive from me would be a two-word suggestion connected with sex and travel.
