They charged our debit card after we left the hote...

They charged our debit card after we left the hotel even though the rooms were already prepaid!! I called the billing department to follow up on that but after being on hold for an hr, no one seems to have a clear answer why we got charged again. I was told it might be related to tax and daily resort fees. However, it never mentioned on the website that there might be an additional charges after we paid the fees. This is not right.