Visitation Questions

My son was visiting my ex during his 30 day summer visitation and began calling and texting ed me repeatedly yesterday due to arguing that goes on in the home, being told by his father that he could get a whippin and he would not stop swinging until his gets tired. My son became so scared and nervous that he began to vomit. I was able to calm my son down while talking to him on the phone while he was in his room upstairs. His cell phone begain to cut us off several times so I called the home phone which my son answered. I gave him some instructions regarding the cell phone to try and get it working again, told him he only had a few more days, try in hang in there for them but call me immediately if anything happened. About 15 minutes after we hung up he texted me again to please come and pick him up because now his father was yelling at him for talking to me on the phone. I went to the house and tried to talk with my son and his father but his father did not want to hear anything we had to say and walked off. I did take my son with me as I knew how scared he was, and I was not comfortable leaving him in what could be an unsafe enviroment. My son tells me often that he does not want to stay with his father anymore on weekend visits or during the summer. He does want to see his father but not spend the night. Are there any legal actions I can take or any organizations that can help us with maybe some counseling for my son and his father!!!