Talking about a time when you calmed an upset customer can be a great example for this question. Be ready to talk about the time you went above and beyond with handling a customer complaint. Explain how you personally listened to every word the customer had to say. Next, describe how you apologized to the customer with a calm voice and sincere heart. Finally, be sure to tell the interviewer what solution you offered the customer. Perhaps you did not charge them for a meal if it was in a restaurant. Maybe you offered a new dish for them to try. Be sure to close with how happy the customer was when they left!
Or, you may approach the question with something you have done during the normal course of the day to go above and beyond for your customers. For example, if you work at a grocery store, you might share that you walk the customers out to their car when customer levels allow and assist them with loading the groceries into their car.