Well dealing with customers you are going to get them types no matter what you do or say they still just want drama. I would stay calm and peaceful and humble and try what I can to get he or she to calm down so we can handle the problem or if that doesn't work I would ask for a supervisor. Remember I have a image to keep for my company. So we may keep doing business with them but there are some that it's so bad that it's not worth doing business with. But when it's all said and done I still say thank you and have a good day.