I did it through their online website and it was sort of strange ... they have you download a communication app that is a little odd....took a few tries to get it to connect.....then once we did, you send them a message like "Day Pass reservation request". It took them a day to get back to us, but once they did, they were very fast and efficient. The other thing is, you don't have to pay upfront, they just take your name and number of guests, then you pay when you get there.
I didn't try calling.