a friend?

So I have this "friend" from way back in middle school.  She was always a flake.  She always annoyed me somewhat.  After I moved away, we kept in touch sparingly. 

More than ten years pass...

Before my mother died, she told me that she was marrying a wealthy man and that she was going to fly me out to be at her wedding.  The day arrived and I had gotten some clothes together to be presentable.  No one ever showed.  We got on the phone and I asked her if she was sure about this guy.  Something happened.  She hung up.

A long time passed and she called to explain that the guy was a con man and told me another number of ills....

nearly another decade passes...

Suddenly, this year, she calls to chat, leaving a message on my answering machine.  I don't respond.

She calls again.  And again.  And again.  And again.

She calls my father's house.

She calls here, again and again.  Sometimes six times in a row.

I don't want to talk to her.  I have nothing to say.  I have nothing to give her.  I don't answer.

How can I answer the phone and tell her?  How can I say I don't want her in my life?  I don't exist in the past.  I am fortunate not to dwell in the hard times of my youth.  She always says I am her best friend.  That's sad.  And I am distrustful of someone so desperate to communicate after so long.

I'm thinking she wants something from me.

It hasn't been like me to reject someone cold like this.  The chill in my persona is a concern.  I've never been the type to unplug my heart...  but I guess that's what I am becoming.  I think it's healthy to try to avoid unhealthiness. 

The woman who can't take a hint is a small speck of a distant past I'd rather forget.  I don't have the heart to tell her, knowing it will hurt, but if her dunning continues... I may have to.  It's bordering on harrassment now.

I'd like to hear what other people think of my situation.  Tell me I'm a cold-hearted bitch or that I'm entitled to live as I see fit.  I'm open to advice.