Occasionally, every business has to deal with an unruly customer, it's part of doing business. No matter how carefully you explain your position, there's one customer in a thousand who will misunderstand and take great offense.
If your establishment is faced with dealing with an unruly customer, try to maintain a clear mental difference between you and your role. Keep in mind that the complaint isn't made against you personally, but rather against the policy, the product, or the service the customer has received. If you make the issue a personal one, you will become emotionally involved, and that's not productive.
Try to remain calm. If you continue to maintain a reasonable demeanor and a relatively quiet tone, an argumentative person will sometimes tone down to meet you. People tend to modulate their tone in kind.
Remember just because the customer is upset, doesn't mean he is wrong. It can sometimes be a challenge to wade through the emotional message and get to the basic issues. Until you've found the core of the problem, you can't resolve it. Consider taking loud or verbally abusive customers into an office or other enclosure that offers privacy where he or she can vent without disturbing other customers or employees. Once the customer is calm, then decide what can be done about the problem.
It doesn't hurt to agree a little. When you ease a complainant by saying, “I understand,” or “If that had happened to me, I'd be upset too,” or even simply “What can I do to help?”, you are not necessarily agreeing with their position, only with their right to be angry -- if the story is the way they say it is.
Throw the ball in the customer's court. Ask them what they think can be done to resolve the problem. Your willingness to listen to what they want will make you appear cooperative and helpful, even if you can't meet their expectations. While you're discussing a possible resolution, remember, not to make promises you aren't prepared to keep.
Nothing makes for a worse complaint than not delivering on a promise designed to resolve a complaint. You can spend hours rebuilding a customer's trust, then lose the effort by not returning a phone call or not having a delivery truck show up on time. Don't make commitments for other people's time unless you are absolutely sure they can meet your schedule. And if you have to break a promise, let the customer know as soon as possible. Be prepared to offer an alternative that will still resolve the problem.
To avoid confusion, have a clear understanding of what you've agreed upon with the customer. Reviewing the conversation gives both of you a chance to correct any misunderstanding and understand what the other expects.