With regards to this post:
Now if I were the customer, and the cashier refused to listen to me that the register did not ring up a sale item properly, and then I am sent to the service desk after the sale is completed, wouldn't I be upset? You bet I would.
And the thing is I worked this summer at a grocery store, and the computer made mistakes from time to time. When it occured, we were told to call a manager immediately and they would handle the situation with regards to making sure the customer paid the correct amount. At Shaw's/Albertsons that meant you got the first mispriced item for free, and all the other items were corrected, by the manager.
But hey, expecting a teenage cashier to care about their customers and service is asking for a lot, especially at times from that community.