When dealing with a difficult or upset customer, the key is to stay calm, listen, and focus on finding a solution. Start by letting them explain their issue without interrupting, so they feel heard. Show empathy by acknowledging their frustration, like saying, “I understand this has been frustrating for you.” Keep your tone calm and professional, even if they’re upset. Apologize for any inconvenience and explain what you can do to fix the problem. If needed, follow up to make sure everything is resolved. This approach helps turn a negative experience into a positive one.