Extremely rude manager

A few months ago i shopped at checkers hyper seeing a few items sell by date is that day. Usually it has a 50% less sticker on but this item didn't have a sticker. So we asked customer care why this items doesn't have a sticker. They said we can go to the till and they will deduct the 50%. So for months we got items with no sticker and went to the till informed the cashier and had no problems. Today was a different story. So we had items with no sticker on but other items had stickers on. So as usual we took the items to the till and the cashoer asked customer service. They couldn't help so i went to fetch an item showing it has already been marked off. Coming back to the till i think it was the manager speaking to my wife saying its against the rules for cashiers to give 50% less if there wasn't a sticker on with the rudest most arrogant behavior treating us like we are trying to steel something rolling her eyes and looking up at the ceiling when we are trying to explain what we have been doing for months. And we understand the rules but thats not what customer care told us a few months ago. If she was friendly i wouldn't had a problem. But it was shocking behaviour of a manager!!!!