What kind of one-time credit card number was that? Are you sure you are even talking about a one-time number? "old number had been cancelled, and the new one had not been activated"? With one time numbers there is no such concept of old and new numbers.
You create a number, you set a dollar limit and expiration date. If you close it no one can bill it. It's called a http://en.wikipedia.org/wiki/Controlled_payment_number