Check Your Slip at Food *****s

Just a warning to all shoppers at Food *****s, check your till slip before you leave the till point. Yesterday I was charged for a ghost item. When called upon, one of the managers told me that Anyone on the floor could have sorted out my problem, which makes me wonder as to why then employ any managers? He did not say what he was about to do, just a short "just wait here". It took about ten minutes for him to find another person and apparently have a look at the CCTV. The cashiers, according to him, works with codes and that is why I was overcharged. This is not acceptable because if she uses these codes only, her training sucks. How do you scan five items and add a sixth without noticing? What does Food *****s do with all the money that they overcharged their customers?