How to deal with an angry customer?

Listen good and try to discover the problem.

Listening will make him calm.

Apologize with a simple smile .

Telling the customer and make him feel that you will do your best to solve the problem and make the customer sure from your willingness  .

When dealing with an angry customer who needs to return an item after exceeding the warranty time frame, it's important to first listen to their concerns and acknowledge their frustration. Then, explain the company's policy and limitations regarding returns, but also offer a solution that can still satisfy the customer, such as a discount on a replacement item or a credit towards a future purchase. By showing empathy and willingness to find a solution,

so an angry client you have to tak breath before speak try to be calm bring hime water cup tel him keep calme and drink water sir i will handle you problem immediatly truste me and juste keep calm & smile you have nice smile sir why get angry you are our beste client please juste give us time to treating your simple probeme 

whithout this way you can not calm an angry client

Calmness is the best solution.

just let him speak and listen him carefully what they want to.

then tell him what is the problem.

answer him politely

You should remain calm, listen to the concerns of the customer and find possible solutions. Apologized gracefully, and most importantly, do not take it personally. 

Let him feel that he shook up the entire organization, satisfy his ego!

Customer gets angry only when he is not served properly, or the commitments are not fulfilled as per him. So what we have to do is to find the root cause analysis from where the issue arise, and we can give the resolution to the customer and make him satisfied and happy. 

I have dealt with my fair share of upset customers over my years in the Service Department at the dealership I used to work with, both as a Service Advisor and the Service Manager. My approach has always been to introduce myself and ask them to accompany me outside or to a private place to discuss their concerns. Once we are away from the public space they tend to calm down a bit, my theory is they just want to be heard by someone. If you take the time to listen to them and explain that you want to help them but you also need them to be part of the solution it can turn a negative situation into a positive experience for the guest and yourself.