Greetings Wendy_G!
Thank you for sharing your feedback about our Tulum & Cenote Tour, it help us to improve.
In regards to the additional $19 USD, when you purchase our product, it's on the "What's included and what's not" list. Also, one day prior to the tour, we send a confirmation mail with the pick up details and the important infirmation for the tour. On this mail we mention this $19 USD per person to be paid in cash.
Once again, thank you for sharing your experience! We hope to see you back again soon at our beautiful destination.
The Travel Experience Group.