I know that most people who work in customer service develop a customer service persona. (Custsersona? No, that's pretty bad.)
I have a "dealing with customer service persona". Unfailingly polite, upbeat, always "don't worry, let's just get this fixed, take as much time as you need", making sure to compliment them to the manager, that sort of thing, even when I'm about two seconds away from bloody murder.
I have never worked in customer service. I'm not sure where I got this.