Happened to me, I didn't have an old credit card. All they did was charge my current card the same amount and also issued a credit on the original transaction.

I think they increased their risk doing this as they already had the money from the first charge (made 11 months earlier) but it was far less painful a process than it could have been.

An additional technique would be to just use another card and then claim a credit card refund after you return as you have documentation it was a duplicate charge