I have only been to Bang & Olufsen dealers in the US and France. I think I have always visited these stores wearing jeans. I just don't recall a sign at the door indicating there was a dress code.
Furthermore as to the forthcoming magazine, I expect that as a registered purchaser of B&O products, the magazine will be mailed to me. OK maybe I'll go to the store to get the magazine if I am sent a notice.
I was at a Bentley dealer last week and I was better dressed. I wore black jeans.
David. Don't be grumpy. Get even. Next time you purchase something at that store, ask to see someone else or better yet complain to the manager. For me, I always make my purchases from the same person and ask for him by name when I telephone or enter the store.