River Island interview questions

The interview was really quick and relaxed the manager was very friendly, I applied for a part time Monday to Friday 11-4 , 12-5 I these were the hours advertised on the website, however when I got to the interview it was totally different hours which I couldn't do, I'm very disappointed that river island did this, I personally believe I didn't get the job because I mentioned I had children and wasn't able to work late nights or weekends I know it's retail, but I feel it's discrimination to be honest!