The best way to do business with a liar is confront them with the truth. Tell them that you do business as a partner. If your lying customer still can't see the light, tell him that you may not be the best choice for business, and that you think you have someone that can serve him better. Then, refer him to the competitor that you hate the most.
Jeffrey GitomerThe key in mastering any kind of sales is switching statements about you and how great you are and what you do, to statements about them, and how great they are and how they will produce more and profit more from ownership of your product or service.
Jeffrey Gitomer