Huisgenoot sales not allowed on Sundays

Good day. As a small business, Huisgenoot magazines gets delivered to me on a Sunday, in order to take a work load off of a Monday. However i may not sell them to my clients before Monday mornings. It's advertised on tv , available from Friday's nationwide! !! So i do indeed sell them to my clients because it's such a huge demand as people relax and enjoy reading it on a Sunday afternoon. Now they don't deliver to me anymore because i choose to sell on a Sunday. What i would like to know is what am i doing *******ly. It's not like I'm selling drugs or liquor without a licence!! I'm delivering a service to the public.