Who do I contact if the man who had stalked me is now using a cell phone in prison to harass me?

I was stalked, harassed & even beaten by this man for almost 2 yrs. It was a living nightmare. Finally he was arrested last October 2010. Court Hearings for approx 4 months & then finally he is convicted & sentenced to California State Prison. 2 months later he is now harassing me from prison using a cell phone. Crazy!!!! Who do I contact about this? What do I do?