First off, 2 year olds developmentally do not have the skills to play WITH others. They are egocentric and often times play alone or along side others but don't actually engage in a back and forth dialog of play. Most simply do not possess the skills or cognitive ability.
It has nothing to do with chosen behaviors but more to do ability. Just as he does not understand algebra right now he does not understand playing WITH others.
Here is an excellent article that explains the stages of play a child will go through in his/her early years. Knowing and understanding this information is vital for caregivers so that the expectations for each child is developmentally appropriate and that lack of skill is never equated with discipline.
http://gemschicagoearlyyears.com/six...social-skills/
I do think it may be time to move on and find alternate care. It doesn't really sound like the teachers or staff truly understand developmentally appropriate practices and when that happens the results often times effect the child negatively and anxiety and stress is one of the most common reactions for them.