"Buyer's remorse" is also a form of dissonance. When we purchase a product or service, we tend to look for ways to convince ourselves that we made the right decision. If the people around us or other factors make us question our decision, we experience buyer's remorse. On feeling this inconsistency, we'll look for anything—facts, peer validation, expert opinion—to reduce the dissonance in our minds concerning the purchase.
Some of us even use selective exposure to minimize the risk of seeing or hearing something that could cause dissonance. Often people won't even tell family or friends about their purchase or decision because they know it will create dissonance.
Asking for a refund, complaining about the product or representative, or having remorse can all be forms of dissonance. If you handle your prospect the wrong way it increases dissonance and they will demand a refund.