14 ways to calm upset customers

General Philosophy:
Don't take upset customers' rantings and ravings personally. Don't get emotionally hooked. When you let him or her "push your buttons" you lose. When you respond emotionally-with anger, sarcasm, upset, tears-you can't respond rationally. He wants to upset you because he thinks you'll give him what he wants to get rid of him.
Make it a gameor challenge to see how many upset customers you can turn around. or challenge to see how many upset customers you can turn around.
 
Look for the "gifts" upset customers offer you. These gifts are what they can teach you about dealing with ugly human behavior. The better you deal with them, the fewer upset people you'll have in your life. They'll see through your body language and composure that you are confident you can find a solution without getting rattled.
Understand that obnoxious customers are often embarrassed because they made a mistake and want to blame it on you.
 
Respond by being reasonable, firm, pleasant, mature, and professional to show them that you're going to do what you think is right no matter how obnoxious they get. They think that being rude is the only way to get action.
Don't give away the store to shut her up. That rewards her behavior and teaches her-and others-that acting belligerently is the way to get what she wants.
Remind yourself that this abusive person must really have problems if this is how he treats others. He doesn't respect himself so he doesn't show respect for others. He doesn't know what you know about how to get people to do what you want-happily.