How to deal with irate customers or callers?

1) Stay calm and try not to take it personally:

• When a client is upset, their emotions can become contagious. Remember, your client is upset about their situation. They are not upset about you.
• Acknowledge the client's right to be upset: “I’d be upset too, if that happened to me.”
• Breathe deeply, unclench your muscles and focus on the client's needs rather than your own reactions.

2) Let the client vent, without interrupting:

• If you interrupt the client, they will become angrier.
• Instead, let the client vent until they start to slow down. Listen empathetically to their issues without interrupting: “Tell me what happened next.”
• Continue to acknowledge their concerns.

3) Acknowledge the client's emotions and apologize, if appropriate:

• Once a client's feelings are acknowledged, they will usually become calmer and more open to solutions.
• If appropriate, apologize. This does not necessarily mean you agree with the client's position. It means you emphasize with how the client is feeling.
• Some possible phrases are:
• "I'm sorry to hear you're going through this."
• Many people would feel the same, if it happened to them."

4) Help the client focus on their current needs:

• Clients may ramble when they are upset. They may even continue to argue with you, after you've agreed with them. When someone is upset, their bodies are flooded with adrenaline and they can no longer tell what's on topic, or off.
• Talk slowly. Calmly ask questions to re-direct the conversation back on track.
• Check for understanding at each step: “If I understand you correctly, you plugged in our product and but it didn’t power on.”

5) Give the client control over their level of disclosure by asking permission to ask questions:

• Some clients may feel threatened when you ask them for additional information.
• Ask permission to ask questions about sensitive topics.
• For example, "To help you, would you mind if I ask you a few questions? Some of them may seem very personal, so if you're not comfortable with a question, please let me know."

let her/him talk and talk then if he/she's tired its your turn to talk and be polite always customers is always right don't give negative answer always give positive one.