[Ripplinger]

Does your bank have an option to login online to check balances, etc? That's about all you can do until they open tomorrow and call them or go there. Even if Kobo declined a purchase, that wouldn't block using your card at an ATM. Unless some automated system thought the Kobo charge was way out of the ordinary for your usual routine and put a hold on it until they verify it with you. I've had that happen with credit card companies in the past (and one of those times it actually was someone fraudulently using my card, so I really can't complain about their diligence in being safe rather than sorry the few times they called to verify legit purchases I made).

Edit: After reading AnemicOak's post below, Kobo declining your card shouldn't block using your card elsewhere.