How to get rid of an co worker that's an stalker?

I use to be friends with a girl from work she started a lot of drama in my life by being her friend. When I told her I didn't want to be her friend anymore she went crazy. Scratched up my car, now for the past two years since that incident. I just want her out of my life. Its funny because since she did that to hurt me. She constantly keeps asking if we can hang out as if she never did anything wrong to me. I told my job about it they did nothing. They even said if i put an restraining order against her that I still have to work with her. I tried everything telling her over ten times no. I don't want to be her friend. I even told her boldly nothing works. She won't get it in her head, she even interrogates me at work about it. I don't feel safe working at my job. She texts me and if i don't respond and I see her at work she questions me about it. She gets mad if I tell her to leave me alone and talks smack. She even try to er me up by being all nice to win me over. Clearly does everything a stalker do to get your attention. Its been so long and she just won't give up. I'm so tired of it I am thinking of quitting my job as soon as I get a new one. The weird thing is every time I tell her "NO" she waits until what I said comes to past and comes back in my face again. Over and over and over and over again. Just a couple of days ago she texted telling me we going to the beach I had to tell her once again 'NO' . I feel trapped because no matter what I say to her I am forced to work with her and be friendly at my job. And as long as I'm doing that she's going to think I want to be her friend and I don't. What should I do guys? I would gladly appreciate the comments.