Primark interview questions

I applied and received an email asking to meet a week later which I then chose a date I could come in for the interview it self. I was a little nervous, I did quite a lot of research on the interview qs and all so I was prepared. I was interviewed by a lovely lady who was very friendly and welcoming which made me feel very comfortable and it was pretty simple and quick and I was very happy with how it went.

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.