Payment According to the Price Written on the Label

Rabbi Israel Cohen, I have a follow-up question regarding a change in price from what is written on the product. Is this not a law of Sodom? The seller, grudgingly and against his will, reimbursed me, in order not to violate the law. There was a mistake in the price on the product. It was a loss-making price.

Shalom and joyous holidays!
As I have already written, in places where there is no clear custom to act according to the law, it is forbidden to demand to be charged according to the price that is written on the product.
However, in places that operate only according to the law, there is a kind of waiver, as if the seller and the customers stipulated that all sales would be according to the rules of the law.
It is possible that the law also recognizes the possibility that if the price does not match the product and it is clear to all that there was a mistake in the coding, there is no right to claim to pay according to what is written on the label. But as long as there is no such claim, the sale is according to the law.