You probably need a different punishment, especially for a teen with austim. When DS (15, AS) has been physically aggressive then I use a simple punishment , a punishment that is very clear, immediate and soon over over within days, a week at most. You could try total grounding for few days, no playstation, whatever you like (or rather, whatever he will hate! ) and then finished and done. If hes often aggressive in school then youll also need to think about helping him to manage triggers better; if its a rarity, then punish and let it go.
Agree sensible rules for going out with him and then stick to them, dont make the rules for going out conditional on something else thats not related to going out. Either he can go out, or he cant (as a punishment), but when he does go out the rules for going out should stay the same.
Changing the boundaries doesn't work, chances are a kid with autism wont understand why you are doing it and will just feel confused and resentful. From his point of view you are just being irrational and unfair. Keep consequences simple and concrete -- and then move on.
I went through patches with my son that seemed similar. I mostly follow the book Divas and Doorslammers and the author says the key is little rewards, little punishments and often small praise.
We found this works - often and small consequences - positive and negative ones. And in parallel good loving conversations where we explain the importance of these rules and makes sure he is on board with everything, at least in principle.
We also put all the rules and consequences in writing and we all signed this 'contract'.
So, it's getting away from simply forcing and policing him and moving towards establishing good rules together.
I don't know too much about autism but isn't it a good and healthy sign if they rebel like neurotypical teenagers? Maybe that is something to be grateful for, even though it's highly annoying.
My stepson is driving me and my husband mad. (He is 15, We have a good relationship, tell him we love him, he tells us the same, he has high functioning autism, he has always lived with us, he has a bad mother that abandoned him at a young age, he has counselling for this just to give a bit of background info, but I really don't think much of that is a prime factor in this situation)
He is being so aggravating and I can feel things starting to spiral and we are at our witts end. It started with him getting angry and punching a kid at school, so he had his boundaries restricted ( coming home straight from school not going to friends at weekends) then we slowly relaxed it, but every time we give him an inch he takes a mile. we let him go to his gf's for dinner, he had to be back at 9, he turns his phone off, doesn't come back till 11, have a huge talk with him in which he strops and comes up with silly excuses (I didn't realise it was that late, my phone was in my bag etc etc) so we restrict again then let him go to his friends after school and tell him he has to come home for dinner, he again doesn't turn up, he again starts with the whole why are we being unfair etc and sulking. He won't accept that what he has done is wrong, ever.
He just wont accept that if he behaved himself then we would allow him to do more of the things he wants but if he cant follow simple instructions then he wont be allowed to do what he wants. If he doesn't follow the rules he wont get a reward.
But every-time we give him an inch again, an opportunity to prove that he has learnt, he takes the mick and is rude again. I talk to him and all I get is the 'its not fair, your treating my like a 6 year old moan).
What is the answer? just keep taking more privileges away until he behaves? it seems endless.