So it's the card processor that assigns the codes, or Visa/Mastercard? If it's the former, then if the establishment changes processors then the code could change? In any case, the cardholder gets screwed if there's a misclassification, and it sounds like we just have to suck it up.

Here's the establishment in question: https://www.playahermosaoyster.com/

Hard to see how this could not be classified as 'restaurant'.