I would really like if someone could share some information on the school system in Turkey.

You see, I have a young friend in Turkey who is now in a boarding school (? I´m not sure what it´s called, sorry), where he live in the school with other boys and with teachers around, so that he can study to get enough study points for university.
Now I am starting to get a bit worried about my friend, because usually we talk quite frequently, but now he just ignore my calls all the time. When I finally reach him he says its because he study all the time and that teachers will take his phone if they learn that he has one.
I can´t see any reason as to why he would lie to me, after all we are good friends for a while now, but when he claims to have school ALL day, including weekends is a little too hard to believe for me. This school sounds more strict then the army in my homecountry, so I am wondering if this really is a fact??