Don’t take it to heart : Mind, the client is not angry with you, they are displeased with the work of your product or for showing the quality of service that you provide. Your personal emotions are beside the factor.
Find a solution: Once you understand why the purchaser is unhappy, it is time to provide a solution. Ask him what he feels should be completed or put forward your own truthful and realistic solution to the problem. In maximum cases, that’s all the customer is searching out —and may bring about providing some degree of satisfaction.