I was in Marks & Spencers yestaerday and saw a couple of really cute dresses so I took them to the dressing rooms to try them on. The dressing rooms were closed. The sales assisant then told me that they now close them during the sales. I explained to her that yesterday was a rare day when I didn't have my very young son screaming his head off and that returning it would be a hassle. She rudely refused me even though i'm a really good customer and shop their daily. I don't understand how this policy benefits their customers. I felt really angry. Am I being unreasonable?