The way you respond to this question will allow the interviewer to determine whether you will be a good representative of their company when serving their customers. The interviewer wants to know that you are ok with dealing with confrontation and that your customer service skills are up to par with what they are looking for. Show that you know how to effectively problem solve and use these skills to retain customers.

Think to a specific time when you dealt with an unhappy customer, yet you created a positive outcome. First, describe the scenario. Then, talk about the actions you took to fix the situation. If the outcome of the situation led to the customer becoming a returning customer, even better as this shows that you solved the initial situation, you created a relationship and built trust with the customer.