being served prime rib when asked for ribeye steak
No. A dish is a combination of the ingredients and the techniques used to make it.


a cheese omelet served in a pie crust isn't a quiche
and a dish of oily raw eggs with lemon juice isn't mayonnaise
a salad with lettuce, tomato, bacon, mayo, and croutons isn't a BLT


If you brought it to their attention and they said your order was correct, they were either pulling your leg, it's some weird idiosyncrasy at their restaurant, or they have no idea what they're doing.

If you didn't bring it to their attention, they almost certainly inadvertently served you the wrong dish. This happens all the time. Being a server is an extremely fast-paced, difficult job where you've got to remember a million things at once. Maybe the point of sale system had a "Ribeye" button right next to something like a "Rib Lge" button for a large prime rib cut. Mistakes do happen, and if you don't let anybody know, they can't correct them.