I want to apologize to a girl after I was told to stop contacting her. Do you think she'll speak to me?
That depends. Are you doing it just so you have a reason to contact her again?
I'm only doing this because I have nothing else to do
You should just let it go. Just stop trying to contact her. She doesn't need your apology.
But I want to say I'm sorry and if she is against it, she should say so.
You were already told to stop, so take those words and remember them. Don't be persistent when there's no call for it.