They first phone you and go over the role, then ask about your experience. Then they do a role play, at the end of the call they'll ask you to come in for a full interview if successful.
They're happy for people who don't have sales experience, it means they can teach you their way of thinking.
The full interview goes over your resume, experience, what makes you stand out, previous career challenges and then a final call centre/sales role play with a member of management.