Empathize rather than sympathizing. Show your expertise on the product/service in question, some authority on what you can/cannot do for the customer and thirdly reassure him/her that you will do your best to save the customer some precious time and the unwanted frustration. In the worst case offer an alternate product offered by another company and refund their money.
mad
Depends on the guy, he could be saying that because he isn't mad just upset, he could be mad but doesn't want to upset you, or he could be saying that because he isn't mad or upset you just took his impression the wrong way.
my guess is they pull away is because they think they can deal with it themselves and some can but others can't. So if they can't deal with it try to help
angry or upset
angry, mad, or upset
Very mad or upset.
When in a store and you are trying to deal with a customer, you are supposed to great them.
how to deal with a difficult customer in a retail store
If you are upset about something that happened during your day
UPSET!
If you are upset about something that happened during your day
depressed