Primark Retails Assistant interview questions

I am so disappointed. I prepared for this interview for a whole day. I arrived 40 minutes early to the Primark-Marble Arch, managed to find customer services desk. After ten minutes of waiting, we were transferred to the employees' area where they took photocopies of our passport and NI. After 15 minutes, I was called in for the interview. The interview started well and the guy was nice. But then...I was told that they do not have weekend shifts that are suitable for me. The only shift they had was from 1pm-10:30pm and as I am under 18 I cannot finish work that late. I was not even interviewed!! When I applied I clearly stated my birthdate and availability.

the interview was easy enough and the questions were expected. One competency question that had to do with team work. The interviewer was quite friendly and willing to help whenever needed.