We had our price adjusted by the Pleasure Park as well (a couple years ago). They quoted us a price on the phone, but when we showed up with a credit card they said "sorry, that was the cash price." But, they didn't tell us there were two rate schedules until we showed up and were far away from the ATM.
"Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover." - Mark Twain