Waitrose interview questions

I applied online, the process takes a reasonably long time but it was relatively straightforward. I heard back in a matter of weeks and organised the date for my group assessment. It was in the evening, I got to the store and was told it had been cancelled! I was disappointed as nobody had thought to let us know, and I had to make way home again with no promise of a reschedule. Again, in a matter of weeks I had an email with an apology for the cancelled interview, and rescheduled my group interview for that upcoming weekend. The interview itself was great, quite laidback and friendly, with about 7 other young people. We had to outline the improvements we would make to a store based on a 'Secret Shopper' review, and then we had 1-1 interviews about ourselves, when we could start etc. I left feeling so positive about the job! We were told we would hear back soon, but if it reached 2 weeks and we had recieved no news, we should chase up the position with a phonecall, which I eventually did end up doing. Apparently the applications were with Human Resources, and should hear back in the following week. Well.... that was about 3 weeks ago and I have still heard absolutely nothing. I have just assumed that I should not expect to hear anything, so incredibly disappointed and confused considering the John Lewis Partnership's great reputation as an employer.