How do you turn angry customers into friends for life?

The following 5 points may be useful:

1. Understand the problem faced by the customer and the interaction of the customer with your company throughly. You should be having a good customer service software for this.
2. Put yourself in customer view and look at what could be the best possible solution
3. Work swift with your team and get an instant solution. In case if you couldn't get a solution right away, plan for a solution and a temporary relief for the customer.
4. Reach out personally from a higher level, acknowledging the issue, show empathy and offer the solution which you worked out exclusively for them. Yes, You should tell them that you have tailored/worked this solution for them.
5. Followup with the customer a week later to ensure that he is happy with the solution you offered and share what you have made in your process to ensure that issues like these will not happen again for any of your customers.

Well said Mr. Emmanuel Wamweta... 

If you handle angry customer first of all make them priorities,releazed them he is valuable and royal customer for you

If mistake. And fault done by him.in this case not blame them. 

Provide quick Soluation and after that day take follow up

Ensure credibility & reliability at all times

Give him some attractive offer at that time and realized they are old customer. 

Thank you for inviting your answer ............................ full and there is no increase them

Strive to make an effort to ensure that the situation doesn't get out of hand.

Make them a priority in your operations & activities.

Make them feel like kings both at and off the business premises.

Make them feel that they are important and that thry are part of the business & not outsiders.

Respond quickly & effectively to their pleas, suggestions or advise.

Regularly visit their premises or workplaces & find out how your products or services are performing.

Ensure credibility & reliability at all times.

Create an a neutral atmosphere for fairness & equity between your business & their welbeing.

Provide them incentives & periodical offers.

Provide technical assistance to the customers.

Thanx for the invitation

My first priorty would be to calm the person down and have an adult conversation.

I will do all in my power to see the issue from the customers' viewpoint.

Smother the customer with kindness, and exceed their need.

Follow up a day later with a courtesy call and send the customer a gift with my thanks.

I agree with your action plan Gopal