Is it right on the part of my parents? ?

I am studying my 12 th standard. As soon as I passed my 10th standard my parents took away my pc,mobile, itouch, and all the other gadgets. Now they want me to slog and study whole day. Recently they promised me that they would get me a ps3 but suddenly they turned me down. They told that they won't get me a ps3. Is it right on their part to do like this? I am depressed. What should I do to stop this?