My casio clpad 330 wont turn on?

i have this $200 casio clpad 330 calculator and i've had it for about 2 months, now it's stopped working and i don't know why or how to turn it on. i haven't dropped it or anything. I have hit the on on numurous times and i have also plugged it to the computer but it does show. i really need some help because it's for school and i'm not buying another 1.