I'm thinking of cancelling a surprise christmas gift my wife ordered
Do you know what gift your wife ordered?
Of course, a painting of a cat. My wife really loves it.
Although you may disagree with your wife's purchase, you should not cancel her order without her permission.  If you do cancel it, you will be showing your wife that you do not respect her or her desires. This will lead her to distrust you and cause problems in your marriage.
I think I'm just going to cut off her bank cards, then.
You're really looking to start problems, aren't you? If that's the path you've chosen, so be it.