Why would even bothered getting your phone and typing a long text to send me when I've explicitly told you I don't want anything to do with you unless you change your mind?
Most Helpful Girl
It would be helpful to know the content of that text. You say it was long, could it be that she has, in fact, changed her mind? Maybe she's too shy/scared to state things directly but a long text generally means someone has something to say (even if they don't say it directly). Is there anything between the lines?
Assuming there really is not and she really has not changed her mind: she might just miss you as someone she had in her life before. I agree that it's not right to text you for that reason when you've specifically told her you didn't want to be in touch.