There are several synonyms for the word "dissatisfied customer," including unhappy customer, disgruntled customer, dissatisfied client, disappointed client, or unsatisfied client. A dissatisfied customer is someone who is not happy with the product or service they received from a company. This individual may feel let down, frustrated, or disappointed in the quality of the product or service they received. Businesses strive to satisfy their customers, knowing that happy and loyal customers are essential to their success. Addressing the concerns of a dissatisfied customer and providing excellent customer service can often lead to a positive outcome, such as retaining the customer's business and improving the company's reputation.