Inscrivez-vous ou connectez-vous pour rejoindre votre communauté professionnelle.
If the customer is displeased you should take that as a good feedback about your products or services. Be patient with him. Show him that you are care about him and you will deal with his complaint seriously
Best way for the sales representative to face a displeased customer, is to listen to the customer attentively and do not argue with him until he has finished his complaint. Ask him to sit and offer him water/tea or something like that. After he is finished you can tell him what you are going to do to resolve his problem. Show him empathy, means you can understand how he feels. Once he realizes that you are on his side, he will cool down.
