Merchants almost never pass along interchange fees to the customer. Instead, it's built into the prices that every customer pays the merchant, regardless if the customer uses a credit card, which means everyone pays for credit card rewards.
Yeah, they include the surcharge in the list price and give you a "discount" for paying in cash (or direct debit).
Some merchants include it as a separate line item. But remember that taxes aren't included in the list price, so it doesn't stand out as much as it does in other countries.