Extend the extensions

I want to hit someone right now...
I ordered some Kenko extension tubes a week or so ago for my Canon camera. Got a superb deal through Amazon.
They arrived today, nicely boxed with my order, and nicely boxed with the wrong mount. Can you spot the problem?

Oh, Amazon were very apologetic, I'll get a full refund etc, etc, etc.
But what do I do now?
Re-order and risk the same thing happening? Or just go ahead and buy the genuine Canon article?

Ah well. Until tomorrow