Family Law Questions? Ask a Family Lawyer Online.
well, you need to go into the court house and see how the service on the notice to change the hearing was "returned" to determine if she lied about service being properly made.
if it is returned as served or unable to serve, then you need to show that you have not moved and were never served that notice. and you can request a hearing on that fact and that will start the process for you to have another hearing on the custody issue
you can contact the TX Bar Association for possible help with a pro bono attorney
here is that contact information