My 14 year old grandson's behaviour has for many years been challenging. He is undergoing assessments for ASD and ADHD. I am looking for advice on how to deal with a particular type of behaviour. If he misbehaves ( hitting sister's, swearing, refusing to go to school) he has a privilege removed ie going on the playstation. He then continues to misbehave and kicks off, often smashing things up and says he might as well as he already isn't allowed on his PlayStation. A recent example is that he has refused to ho in school and he was told that if he doesn't go in his PlayStation controller is being confiscated (it operates the TV). He is now saying he won't be going in school tomorrow unless my daughter gives him his controller back tonight. He spent last night kicking off because he didnt have his controller. It is like he is trying to bribe her, She has said no and that he will get the controller back tomorrow after he has been in school. He is saying he will not go in school then. This leaves her in a difficult position over the Xmas period as tomorrow is the last day. Any advice is appreciated