This literally just happened to me. I wondered if your account has since unbanned? maybe they just have a timer where it will auto unban after a while. 

@builderofcastles. I wondered if I ask them to delete my affected account completely and reopen another one if that would work again. 

If they truly care, they could've enforced the quantities limit like how amazon does it where there is no way to buy more vs ban people right out where but other things.