I was first pre-screened over the phone by a recruiter who asked a few questions about my experience with call center environment and sales. She invited me for an in-person interview about a week and a half later. She asked me about a specific time when I dealt with an irate customer. The in-person interview was very focused on my experience dealing with specific types of situations with customers. Basically they want to know how you react with difficult people. They will make you role play a live situation where one interviewer acts as an irate customer and you have to solve an issue for him.