Please help,I need advice. Huge backstory, so please bear with, I'M NOT A TROLL.My DS12 is getting out of control. He got in with a really bad group of older girls at school last year, and even though we have moved him to a different school, he continues to keep in contact with these girls online. He is not allowed social media due to being underage, so he went behind our back and set up an Instagram account to keep in touch with them. I monitor his internet use, but its been a hectic week, so I didn't find till this weekend. What I found shocked me, these girls have been sending him porn and encouraging him to go through mine and DH's personal things when he's home alone and report back to them with what he's found. When we confronted DS he went apeshit, screaming that we were intrusive and over controlling and shit parents. He even pulled out his pocket knife and waved it around threateningly. Dh grabbed the knife and DS ran out of the house. DH went looking for him, but he ran off everytime Dh got close. In the end we had to call the police to pick him up and bring him home. We asked the police what to do, and he just shrugged and said he's probably embarrassed but don't worry he will grow out of it.
The next day we sat Ds down and said that there would be no more smart phone or internet access, and he was grounded for a month. He responded by hurling his skateboard at my head. Which we have now confiscated. The day after that he accompanied me on a walk to the shops and while I was paying, took off again. I gound him at park with a local boy (who is a good kid), borrowing his phone. I went over and said "sorry x, ds is grounded and can't play right now ,you can have your phone back, ds is coming home ". Ds just smirked and handed the phone back, said goodbye to his friend and came home in a good mood. Later that night I checked his Instagram and saw he had used that time at the park to contact one of the girls, asking her to delete the messages and he'd be in touch later.
I'm at a complete loss, how do I enforce consequences, when its just a game to him? He shot up over lockdown and is bigger than me now, and seems to think he can do as he pleases. I've made an appointment for us to see a counsellor later in the week. Has anyone else had a teenage son who has behaved like this?