On Scary News

As some of you know already, John is currently living with his Mum up in Scotland. He has enrolled in college and has very little contact with me. In fact, the only contact I've had is "Can I have some money" or "Can you top up my phone." Not even a "Hey Dad, how's you?" but hey ho. Anyway, I had a call on Saturday letting me know a side of the story up there I didn't know.
When John's Mum left, she went to live with Sam, the convicted wife beater. The old addage "A leopard never changes it's spot's" rings true, and sure enough about October last year he beat her up. This bothered me obviously, but that voice in my head just said "I told you so," and life went on. Not surprisingly, she then finished with him. As far as I knew, he was out of her life, and then last week I got the revelation that he'd been taken back. I'm guessing this is why John wanted to stay up there, because from what I know of Sam he's a nice enough guy 99% of the time. He'd take John fishing, and they appear to be playing happy families.
Anyway, this call on Saturday came. Sam had done it again, only this time John had tried to protect his Mum by getting in the way. Sam had clobbered John to get him out of the way, and laid into his Mum for a second time. She'd ended up in hospital a second time, and John had stayed by her side.
The problem with this is I feel so helpless. Whilst John is in Scotland, he believes he has no need for me, and this is encouraged. I genuinely haven't heard from him more then 6 times since he announced via text that he's not coming back. I haven't spoken to him on the phone, I haven't had an email from him. Everyone is telling me to leave him to do what he wants, he'll realise what side his bread is buttered, but this is breaking every natural rule a father has for his son. And now this events of last week have made me feel even more helpless. When John lived with me, I made sure he contacted his mother regularly. He phoned her twice a week, and I know he chatted to her on facebook. I could contact social services, and I think I'd have just cause to have him withdrawn from his mother and forced to live with me until he's 18. The problem is, he'd hate me and as soon as he's 18 he'd go back to her and resent me even more.
In the meantime, I have to sit back and receive phonecalls from worried family, and be absolutely unable to do anything.