I'm wondering what kind of rights I have in this situation, and what kind of legal action I might take.

A certain person who I do NOT want any contact with has been harassing me for over a month. I have refused contact with her and told her I did not want her to talk to me. While I have been able to block her from Internet social sites and screen her calls, she texts me all too often. And she will resend texts sometimes five or more times. It's a nuisance, it's unwelcome, and I told her if she continued to text me, I would look into taking legal action. I am trying to figure out what I can do to keep her from contacting me. Tomorrow we will see about buying a new phone which CAN block people, as my current phone CANNOT. I'm hesitant about changing my number because we still have mutual friends, and it'd be too much of a hassle if she would just grab the number from their phones.

Does anyone have any informational links, or personal advice, for me?