No one here can really be responsible for a treatment started in another country unless they take over the whole case and re design the treatment plan as needed (if there even was one).
What you are paying for with the orthodontist is the actual treatment in terms of time, skill and judgement, not just a hand full of brackets. You need a Doctor who can make the brackets DO something. Probably best to travel back to Mexico and hope you get lucky or start over with a new Orthodontist up here where he can design and manage the treatment properly. It might be good to read some reviews before you start up here also as some of the cut rate Corporate places here are almost as bad as Mexico. I have seen some really bad stuff from both places.