My vindictive streak would be telling me to mail a copy of Crisis of Conscience (or your prefered aposto-bestseller) right back at them, and to tell them both to blow their thanks/invitations out of their ar$es. They sound crazy, so I'm not sure anything you do will get through. Very difficult. They're not operating in the parameters of normal human behaviour.
Good luck,
ig.
(I thought your name was deb as well)