yeah, sounds like an impossible situation to get our of over there. also sounds like facebook have essentially monopolised messaging services in Mexio. I also read something similar about Brazil too.
It's really amazing to me that the killer features of WhatsApp - no spam and no usernames/passwords to keep track of or get hacked - were made possible by simple SMS authentication. The whole lack of spam via SMS authentication itself and using the phone system as a proxy for real humans is something that sounds so simple now yet eluded people for the longest time. Maybe it was because SMS messages used to cost something for many years, at least in the US.
It really elevated the app to something else when we were in a sea of spam and dealing with old people who forget their login names and passwords who didn't like having to login.
And FB made a great call about it being worth $20B even though it was shocking at the time.
I am French and we do use WA a lot but only on a social level, not (yet?) as a way to contact businesses.