Store not adhering to standard operating hours

I placed an order online(Nelspruit promenade store) at 15h42 to be called by someone from the store to inform me that they are closing at 15h45 even though the website and store decals showed a different closing time. When I walked in the shop to collect the pizza I was met once again with hostility, a guy that was at the cash register together with a lady that was walking from outside both shouted "we are closed" without even greeting me even though it wasn't yet closing time as per the decal on the door. It is not the first time that particular store did the same thing, I will not buy from that store again and will make sure that all my friends and colleagues never buy anything there again because they have also been complaining about the poor service from that store. Why do they have decals stating the closing time to be 16h00 if they are going to close the doors at 15h45 and not accept any orders from customers at 15h40? Why don't they just put decals showing closing time to be 15h45 and why does the website still give customers an option to place an order with the store if they are closing 15 minutes before the real closing time? Cashing up, house keeping and other store logistics should not negatively affect customer experience .