Best friend?

I'm sure everyone has friend. What would you do if your 'best friend' left you when you needed her/him the most? That she/he ignore you when you tired to talkt to her. That she/he would talk to everyone except you and then say that you were ignoring her. What would you do if this 'best friend' heard people talking bad about you and said nor did nothing about it. Is this a kind of friend you would like? Would you even call her a friend? What if she asked you to forgive her for what she did but continued to ignore you. Would you forgive this best friend?