Happy you have a good time! :)
Concerning the additional charge, remember that you booked it through a third party where the fuel fee is not included. This was not a surprise as you were aware of it. It was advertised on TripAdvisor before you made your booking that there will be an additional charge for the fuel and tax fees.
We arrived early for our 4:00 time we were pleasantly greeted and even told we could bring our vehicle over to park near the dock and would be given a parking pass. They immediately got us ready for the tubing part of the package. Great instruction on both rides and it was a blast on both rides the view was amazing on the parasail portion and opted to get the pictures which I haven’t downloaded to the computer yet. I would recommend this package to everyone.