Very important appeal

Reverse shopping is already covered by the no griefing or stealing rule. Players aren't allowed to take items from another player's chest without permission regardless of where it is, what is in it, or whether or not its claimed. Although the shopping district and shops in general are slightly different, they still follow the same principal: customers are given permission to take the item for sale out of the chest/shulker as long as they replace it with the price listed. Assuming the price was in diamonds: the reason you were banned from the district is because you did not have permission to take their diamonds out of their chest, you only had permission to take the item for sale and replace it with diamonds.

Nope, I'm not a moderator. I'm just commenting as a player who's been around long enough to understand how the rules work. I was trying to clear up some of the confusion you may have had. As far as the status of your appeal, or chances of being unbanned that's completely up to the moderator/admin who originally had punished you. However, I wish you the best of luck.