Logically if you have been put into F for a C price, albeit through some sort of seating gymnastics, you've won. Explain to wife that you've got a head start on the next trip. If you are in Flub it's still a win.

If you find yourself in C I'm sure there are grounds for complaint but at least you are both not upset and can discuss how to tackle the issue clearly. It certainly seems unfair in that instance.