I agree with this^^, HP. You can't stop her from trying to contact you. If you could, I bet you would have done it sooner. Your reaction is all you get to control here. All you can do is what has already been suggested about reminding her of your boundary and leaving a text or VM. You can choose to not respond and/or ignore her.
Now seriously, you need to get on to something else. You are obsessing over this a bit, don't you think? Of course, I suppose a woman like her could make anyone break out in hives at the thought of another contact.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!
Your reaction is all you get to control here. All you can do is what has already been suggested about reminding her of your boundary and leaving a text or VM. You can choose to not respond and/or ignore her. 
