Can my ex-husband's new wife block me from calling my daughter?

My ex-husband and I have a 5 year old daughter. I am the custodial parent but at times if there is an opportunity I will let him spend more time then granted in our custody agreement. I only do this for my daughter and because he is in the army and often deploys for long periods of time. At the moment she is staying with him in the Alexandria, LA but our custody agreement and my daughter live in North Carolina. I was being nice because she starts kindergarten in the fall and wont be able to see him as much and he is deploying again in the fall however, I am starting to become quite angry with the situation. His new wife has blocked any number ociated with me from calling any number I have for them. Is this legal? Can I persue this further since my daughter is there until may?