As much training as we can provide and as many resources that we create for customers, undoubtedly you will one day be faced with an upset or disgruntled customer. When this happens take a deep breath and try to remember that customers are the reason we have a job and a reason that we stay in business. They might not always be correct in their assumptions, and their requests may not always be feasible, but they should always be handled with care-even those who seem to be a bit difficult to handle.
There are many reasons why a customer/client may call in upset, some of which may not have anything to do with you or your position, those reasons range from a bad experience to bad information, to outside reasons that are beyond our control.
It is best practice to not match their anger with your own. Stay calm and patient while speaking to them. Anger from you will only amplify the situation.