H&M interview questions

Group exercise consisted of 9 interviewees, later split into groups of 3. Questions from 2 managers directed at entire group. Received a rejection letter 10 days after interview, decided to challenge decision as I felt i was subject to age bias (was the eldest amongst candidates, others except 1 were students) Did not receive any response to request for feedback, called h&m head office who were unable to help provide any contact details. Was put through to customer service who couldn’t help me. Tried other means of requesting feedback to no avail. Very frustrating for someone trying to better themselves during interview process especially as I was shortlisted in the first instance and have also had 4 months of experience at h&m before and have worked in other retail stores for 15 years