That one sign, ugh.
I had a guy that made my blood boil about that once. The price on a box of folders went up like $.20. There was a four foot section of them. Something like 50 price tags in there for them. The guy that changes the tags, missed one.
This guy comes up with it, and it scans at the higher price.
Custy: "That's not right. It is [old price], it has always been [old price], that is the right price. You have to give it to me at that price. Why did it change in your system? Your system is wrong, it is supposed to be that price! You need to fix it now."
Me: "Sorry, the price went up."
Custy: "No it didn't! I can prove it! There is a sign!"
I follow him out there and yep, one missed label. I take it destroy it, and adjust the price, for that one, because it is only $0.20 and I want to get him out of there.
I said: "Look, the price went up. I am giving you this price, because we missed ONE label. You will never get that price again. If you ever come in here to buy these again they will be at the NEW price. The system is NOT wrong. YOU are.
Me: "But nothing. Do you want these or not? If not, I will put them back on the shelf, and they will be at the right, NEW price."
He shut up and bought them. Never saw him again. It was probably not my best "customer service" but it was nice opening up on him a bit.
Of course a long time has passed and I would probably be fired for that now. I have lost the nerve to fight back, self preservation and all that. Back then, I didn't care. I still have the hate for the one label though.