I did use a credit card and have already talked to my credit card company about the possibility of disputing the charge, but check out AquaWorld's response:
"... if you like we can just open the dates you chose and your reservation will still be valid for when you want to use them. The only reason I suggest this is because when we process refunds without the credit card here, we have experienced delays in the clients receiving them. This delay is not caused by Aquaworld you understand. It seems to be communication between banks here and in the States. If you still have plans to visit Cancun, it would be better for you to keep the reservation. They are valid for two years."
I then reiterated my desire to cancel the reservation and they said, "ok, sure. We will inform the account department for you so they can proceed with your refund."
Then, in their follow-up email, "As I mentioned, there may be a delay with the credit reaching your account due to the fact that we do not physically have the credit card here."
donooo - I like your style. If I haven't received my refund by the time I go to Cancun in mid-April, I may consider your suggestion.
Thanks again . . .