Warning: Refunding to a different credit card.
A few months ago we had a guest book from the UK. The booking was a good one: 7 days. They wanted me to take the payment in full which I did. A few days later they requested a full refund (minus our fee) as their trip had been postponed. They also told me that their credit card had been stolen and that the money needed to be refunded to a different account. Because it was a large sum of money I visited our local bank.
This is a 'trick' to steal or launder money from one account to another. The bank told me to refund the money (in full) to the original account - or I would have to refund it twice.
Basically the moral to this story is to NEVER refund to a different account, only to the one that made the booking.