Lynn Shanghai Cuisine - Sydney. 3% Surcharge. Failure to mention it on their menus and signage.
I complained, mentioning they're required to have this showing before I enter, initially, they said they wanted another card, then they would accept my Amex. I forced their hand to accept it. I called Amex shortly after, who are now investigating.
Also, they had plenty of Amex collateral (like Bill folders, welcome signage, stickers, etc). They would have also gotten a nice merchant rate from Amex and they're still passing it onto the customer! Two bites of the cherry isn't fair to cardholder or Amex.