Answer: Encourage Amanda to complain by listening without interruption.
Explanation: Based on the content, Amanda's dissatisfaction could be inferred from the fact that the sales people failed to pay necessary or adequate attention to customers when trying to make a purchase. These sort of customer service behavior could lead the customer to believe that he or she isn't important, which is a bad customer service behavior. In other to correct or make amends, the manager must encourage Amanda to make his complaint, giving him the necessary attention and audience, which the junior staff didn't afford him.