Ideally it is too late, but if you had them now you probably could plant and would get something, potatoes are easy.

If you could cancel the order, try to do so. They probably do not have them, or if they are just sitting somewhere waiting to be fulfilled, they probably will be less than ideal. If you have paid, complain and try to get your money back either way.

Last year as I harvested new Red Norland potatoes I planted russet potatoes and got a good harvest. It's not too late for your zone. I think it's smart to plant your seed potatoes for the following year late to cut down on your storage time. Same thing goes for potatoes you want to eat all winter.