This is incorrect. It would not even make sense on its face, as all business costs get passed down to customers. If they did not, then the business is losing money.
As of 2010, Dodd-Frank legislation explicitly made it illegal for payment card networks to prevent merchants from offering discounts for different payment methods:
https://www.ftc.gov/tips-advice/business-center/guidance/new...
> A PCN cannot stop you from offering your customers a discount or another incentive for using a certain method of payment, as long as you offer it to all your customers and disclose the offer clearly and conspicuously. For example, you can offer your customers a discount or a coupon if they pay with cash or a debit card rather than a credit card.
In Mar 2017, Supreme Court went further and said state laws banning credit card surcharges were a violation of merchants’ first amendment rights:
https://en.wikipedia.org/wiki/Expressions_Hair_Design_v._Sch...
What you may be thinking about is rules prohibiting charging different payment card network prices for various credit cards (i.e. different price for Visa vs Amex vs Mastercard vs Discover). This was deemed allowable by the Supreme Court in Jun 2018:
https://en.wikipedia.org/wiki/Ohio_v._American_Express_Co.
As an aside, this Ohio v AmEx ruling was of great benefit to tech companies that operated market places, because
> This decision was considered to have created a new type of rule that could make it difficult to seek antitrust litigation; with credit cards being a two-sided market serving two distinct sets of customers, a successful antitrust argument would have to show how both sides of the market were harmed.