I'm not sure if you've been able to reach them, but I emailed them today just to confirm a reservation I made in January, and they responded within an hour. I'm not sure why they wouldn't be returning your emails. Maybe try them again? I know that has to be very frustrating. I'm sure these are the methods of contact you've already tried, but here is how I have been communicating with them.
+52 (983)103-5955
reservations@chacchobenruins.com
Best of luck, and hope this helps in some way!