Ex Wife not informing me or allowing me to talk to my children?

I am currently in Korea and before i came here i had to go through a court hearing in order to see my kids before i came here. I did win that hearing but here is my question in my divorce decree it that my ex and i have joint custody and that we both have decision making responsibility. But when ever i ask my ex for information about my children. I have asked her about what school they are going to, who their doctors are, what their extra curricular activities are just general information about them and she will not talk to me or let me know. She also did not tell me that she has gotten remarried or that she was living with another man. I have also on many occasions tried to set up a calling schedule so that i can talk to my sons but she just will not follow it. Even though i have the right to call any time during the waking hours i am trying to be nice and set up a call schedule and she wont even help me with that.. Can anyone help me with figuring out what i can do to stop this?