Use three words to describe yourself.

"I am reliable, cool-headed, and a savvy communicator. In my previous work, I had a reputation for reliability, so both coworkers and customers knew they could trust me. My work was consistently excellent, and I always tried to manage my time well. I don't easily rattle. I know that while my experience as a Customer Experience Specialist is generally positive, there is no getting around a difficult client. There is no secret that I've unlocked when it comes to pushy or rude or even nasty customers, but I can say that with my best effort, I don't react when I become the target. As much as I can, I redirect the energy toward finding solutions. This is where my other most notable skill comes in. I'm a good study of people, and I always try to meet people where they're at. I've found that between sincerity and sometimes even humor, that I can assuage angry customers while I work on finding a solution for their grievances. This is why I think I'm perfect for this role at XYZ Company."