I feel sorry to hear this. $30,000 is a large amount. Many of us work for many days in order to earn this big sum. Your Yan has no conscience at all. I have the same experience as your family. This just happened 3 months ago. Though the amount I paid was not as big as yours but every time I recall my experience it makes me .
Don't you post her name to the Blacklist?? And write to the immigration to tell the story so that immigration has a record. I heard that it works to some extent to avoid her finding some other jobs....