Mine was with a group of about 8 and we were all roughly the same age: 16/17. It was weird. firstly we did this ice breaker where u have to ask each other questions such as 'do u like jazz music' which was like a stupid thing you do on the first day of school.
then we were given a list of questions to prepare our answers for and say it out aloud infront of the group,, the questions were along the lines of ; are you at college? do you want to go to uni? what are your ambitions for the future? and then onto the job related things like why would u be good for this job? and what does customer service mean to you?
we then had to split into 2 groups and were given a product. we were given a dustpan and brush and the others had a baby bottle. We had to think about the qualities of the product and had to try and sell it to the opposing team, for example i sed something allong the lines of 'this new dustpan and brush from Addis's new slimline range is perfect for clearing up any sort of mess whether its on the floor or in a gap between your kitchen cabnets. the new flexi grip handle allows you hold the brush with ease etc , you get the picture llol.
at the end of the interview we were intervewd seperatly for only about 10 minuites, where she asked me things like 'how could i give a good customer sevice?' and 'what could i contribute to the partnership?'
as for wht to wear - presuming your a girl, a smart top, black trousers, black shoes. the guys wore shirts and smart trousers. thats the way it was for the majority, mind you a girl did turn up in jeans and tshirt and got a job lol