The credit card companies themselves have similar rules . . . but try enforcing them.
EVEN THE STATE charges you a couple of points (2.7%?) at the DMV if you elect to pay be credit card!! And that is a surcharge added. They don't offer a discount paying cash (that's the same thing anyway).
In the past I called the CC company to report a business that was doing this (it was a gas station I didn't like, not a gun store) and they told me to call the bank (???). I knew that would go nowhere but I called the bank and they told me they have no such rule at the bank and if it's a credit card company rule I should call the credit card company.
Nice, huh?