They will ask you a few basic questions. Tell me a bit about yourself? What are your greatest strengths/weaknesses? Tell me about a time when you went above and beyond with customer service? How would you handle yourself when there are a lot of customers and you are the only person available? What qualifications do you have that would make you an ideal candidate for this position?
Make sure you are prepared to ask a couple of questions of your own, such as, what is the next step in interview process? How will I be notified of my application status? When would you like me to follow up with you for a face to face interview?