First you ask their name. Make a repore with them. Then listen to the customer. Sometimes people are yelling at the situation. Not at you personally. They just want the problem solved. Before I put an upset customer on hold I always ask for their phone number and tell them if we're disconnected I'll call you so you don't have to wait again. Which is very frustrating. I always due diligence go the extra mile. By the end of the phone call the customer is calm and the problem is resolved. You don't know how many times a customer will say to me "I'm sooo sorry I was rude to you earlier".