A few years ago, we bought OBC partly because of a favorable exchange rate on the Can dollar. Rather than register a cc, we used the OBC as a deposit against any charges. When we went to Guest Services the last night to claim the remainder, they insisted they couldn't give it to us and a cheque would be mailed to us. The only way they would have given cash back was if we had of deposited cash (rather than OBC) into our account at the beginning of the cruise. My cheque eventually showed up 6 weeks later. DH's required a phone call before it was mailed.