Disagree.......I get a printed receipt for all my purchases....even from the gas pumps these days . Change my CC and THEY become the thief...........
If the shoe is on the other foot, the merchant makes a mistake so that the transaction is 10 times the amount it was supposed to be (but that is what is printed on your receipt) and you subsequently discover the mistake, you are on the phone immediately to have them adjust the transaction to the correct amount. If the merchant insists that the amount on the printed receipt is the amount, your next call is to the CC company to insist that the CC company adjust the charge via some sort of dispute process. Either way, an adjustment credit to reflect the correct transaction amount is very easy. An adjustment debit would also be very easy. It might be that the merchant has to have a letter sent to each customer first, indicating that the transaction that occured at the specific time between 10PM and Midnight for the specific quantity of gas was incorrectly charged at a price of $0.329 rather than the posted price of $3.299 and that a charge in the amount of $xx.xx to make up the difference would be applied. But with notification that a correction was being processed, the transaction would be easy to accomplish and the retailer would be perfectly within his rights to do so.
No, adjustments are common and legal.