As far as people saying, just go and tell the cashier. Sorry, but it's not so easy. You try asking the cashier to correct something after you just paid with your debit card and she hands you the receipt and you see overcharges. They'll say, sorry, I can't do anything about it from here. You'll need to step over to customer service and wait in a long line for half an hour to get a 25 cent credit.
Also, the store which had the 99 cent endcap display as I mentioned does not have those "shopper cards". This was nothing but a nefarious attempt to defraud customers into thinking they could get cereal for 99 cents. And it happens all the time because grocery store prices are down to the margin and they try all sorts of tricks to make an extra buck. They also don't take down the previous weeks sale items signs until the middle of the next week. Customers grab the item thinking it's on sale not reading the fine print and it rings up at full price at the register. How many of them catch it or want to deal with the hassle of stepping over to customer service to get their small credits after the bill has been rung up?
Also, the store which had the 99 cent endcap display as I mentioned does not have those "shopper cards". This was nothing but a nefarious attempt to defraud customers into thinking they could get cereal for 99 cents. And it happens all the time because grocery store prices are down to the margin and they try all sorts of tricks to make an extra buck. They also don't take down the previous weeks sale items signs until the middle of the next week. Customers grab the item thinking it's on sale not reading the fine print and it rings up at full price at the register. How many of them catch it or want to deal with the hassle of stepping over to customer service to get their small credits after the bill has been rung up?