Konditor interview questions

Received a phone interview - asking questions such as why this job and if you were a cake, which cake would you be. Got called for a group interview. there were about 8-12 of us (all girls/students), they split us in groups and made us do a role play of what good customer service is. We then showed it to the rest of the group. Each group had a store manager monitoring their group. Then, we had 1:1 Interview which was pretty straight forward. They asked about experience, how do you react to change, have you ever had to tell a colleague off. etc It was successful that the manager gave me their number and told me to call back to schedule a trail day which she said lasted about 5 hours. The trail day was on a day she wasn't working (manager), and when I came in I could tell they weren't expecting someone like me because I was an ethnic minority. For the trail I had to follow one worker throughout the shop, it was okay at first but then they kept putting me at the sidelines making me clean the floor, wipe the dust, change boxes. I felt like a second class citizens (I even overheard another colleague asking the person monitoring me why they were giving me all the 'boring stuff'- I'm even more qualified than them). I knew from then I was wasting my time. There were people on the shop floor who hadn't been in the country for long and also made me questions how they got the job (on that particular store I went to). I got send back home around 1hr and a half. I did everything they asked for to the best of my ability - and I did not feel comfortable there and hoped they rejected me. About a week later I received a rejection. I was happy and annoyed. Annoyed because I wasted my precious studying time on a unprofessional place with no respect. Going through the whole interview process was pointless. I find the interview system atrocious. Lastly, I find that place very unhygienic, they have food which isn't covered, and on top of that I even saw flies land on the food. The workers did nothing about it. It's absolutely disgusting. When I was cleaning the store it was very dirty. It's as if they don't clean it and expect me to clean up their mess. I wasn't even treated this bad on my work experience. Remember this is just my personal experience it doesn't mean it will happen with you. I've also realised they always have vacancies up..... But similarly to the review above, I do feel I was discriminated for my race and belief.