I applied online via the website, then was contacted for a group interview. There was around 6 of us, we all met with the interviewer and he asked us general questions about what we had done so far (uni, college etc), asked about our availability.

It is more of an induction than an interview. If your CV is good enough for them to contact you, you will most likely get the role. Demonstrate knowledge in customer service and your ability to learn.