Question about gas pumps/oil companies?

That's why we have the department of weights and measures who is responsible for everything from making sure gas pumps are operating and charging us correctly, to whether the shelf price at the grocery store is accurate in the registers. There is such a thing as a mistake, but chronic problems make companies pay really huge fines (makes cheating VERY not worth it) and face the possibility of losing their license to sell the types of items in question.