How do I enforce cell phone contact?

My boyfriend and his ex wife have a shared parenting agreement for their 11 year old daughter. in that agreement they are both to have phone contact with their daughter, especially when she is with the other parent. The mother provides her with a cell phone, however, she is not ordered to do so. The past 2 weeks my boyfriends phone, my phone and his land line have been blocked from calling his daughters cell phone. he sent a text message to his ex who claims the phones are not blocked. We called AT&T and Verizon who is stating that there is nothing wrong with the settings and should be able to call, they cannot come right out and say her phone is blocked since we do not have access to her account. Is there any legal rights he has against her?