Hi there,
Thank you for sharing your comments with us.
You made a booking for Cancun area however you was going to Playa del Carmen, as explained this area involve another price. Few minutes after your booking we contacted you and we advise about the situation and the process to follow to solve this however you never amended your booking (you never paid the difference). Since you didn't amended your booking and that is no possible to paid at the the airport on arrival you was deserving a full refund for the booking wrongly made.
Next time made sure to follow the instructions to avoid any issue. We are here to help you.
We hope to see you soon in Cancun.
Cheers,