Order was canceled for no reason.

The order I had placed have been canceled however I still have been billed for it. Yesterday night the order was said to be processing. I don't understand why it was canceled at all I haven't gotten an email saying it was canceled I didn't get any notification stating the order was canceled the last notification was "We're processing your order" and that is pretty much it. It was going to be delivered by Express Delivery, honestly I don't know.