After passing an online assessment (where you receive feedback fairly promptly), and completing the application form (which I took about 3 weeks to hear back from), I was offered a choice of times for an assessment centre, held in the offices of the Leicester Highcross store.
Although I had been primed for team-based tasks, in practice there was only one other person there on the day. After introductions, we had to complete a task where we had to match a product to a hypothetical customer, and then if I recall correctly we had to 'sell' a particular item.
This was followed by separate solo interviews, with the same person. These weren't really unique.
My memory is somewhat hazy, but I recall the entire assessment centre taking less than the 2 hours I was warned to allot.
During the process I recall there being one interviewer, with someone else there taking notes.
My interview date was July 1st, and it took until August 7th for me to hear back.