As long as you have some customer service face to face experience that should help, even if it means volunteering for a local charity shop or something similar.
Your questions are good and it's well worth preparing, I've been on 6 interviews I think, never got the job. Just don't think it was meant to be. Still, back when I was 18 I got interviews with both Virgin Atlantic and British Airways with only a voluteering role. I just never had enough experience of the interview to get through.
They ask alot of situational questions, name a time you delivered excellent customer service, a time you had to deal with someone difficult. That sort of thing. The other questing I find you can blag, it's these questions you need to think of answers too. Most of all be confident, don't be so wound up about getting the job, if it happens it happens. I find I get myself jobs left right and centre with this attitude because you come across as calm under pressure - always a good trait!
Good luck
