Good customer service is a part of the foundation of any successful business. In today's highly competitive environments, customers can afford to be picky about where they want to spend their money. If you want consumers to choose your place of business, you'll have to take steps to ensure you provide good service.
You also must maintain these high standards once an individual becomes a customer. Keep in mind, you'll also have to be prepared for the fact not every customer will be happy with every experience. At some point, it is likely a person will get upset. If an angry customer situation occurs, it's important both you and/or your employees to know how to handle it.
Listen to Your Customer
Listening to your customers, no matter how angry they are, is a key factor in quality customer service. Don't simply dismiss what a customer is saying and view him or her as a disgruntled person. If there is anger, this means something has caused upset. It may or may not be your organization's fault. But you won't know unless you listen.
Don't forget to be empathetic as the individual expresses concerns. Offering empathy doesn’t necessarily mean the customer is right, just shows the person his or her concerns are being heard. Sometimes all a person needs is to feel as if they are listened to and/or understood, which you can provide right from the get-go. In my experience, this also can help quickly defuse a situation before it escalates into an ugly one.
Be Respectful and Friendly
Even in the face of anger or frustration, try to do your best to maintain your composure and not take the complaint personally. While it may not be the type of situation you want to give your biggest smile, you should always treat angry customers with respect and friendliness. Show them you care by giving your undivided attention and show the customer you want to help resolve the problem. Additionally, as Forbes notes, remember to apologize for their dissatisfaction. 
Avoid Being Argumentative
When faced with an angry person, it might be tempting to express your own frustration and anger. It is important to avoid this at all costs and refrain from being argumentative. Conflict is not the most pleasant situation to have to manage, but you do not want to compound the situation by adding your own frustration to the equation.
Adding additional anger to the mix will not lead to a solution, but instead will likely escalate an already problematic situation. If you, or one of your employees, respond negatively to a customer complaint, this typically won't reflect well on the business. In the age of social media, this quickly leads to bad feedback that could potentially spread like wildfire, creating a negative image of the company.
Be Accommodating and Strive for a Solution
Upset customers need to express their dissatisfaction, and by providing an ear, you have already started the accommodation process. Next, you can kick it to the next level by seeking a solution. Ideally, a customer service representative should be able to effectively resolve problems, however it is not always possible. If you do not have an immediate answer, then provide the person with reassurance you will get one.
Customer service is the type of job that requires strong people and other soft skills. In any anger-related situation, it is a good idea to strive to maintain composure and professionalism at all times. You or your service/product might be criticized, however, accept the feedback. If the customer is truly wrong, you'll know this, but also keep in mind the negative feedback also might be spot on and this could potentially be a golden opportunity for the business to make improvements. Businesses that routinely dismiss customer concerns or complaints will find they quickly lose loyalty and market share to competitors.
Customers are a big part of business success. In order to continue the relationship, it is important to handle complaints effectively.