mags, call the phone company.
Most have to have SOME way to disable text messaging, as they need to be able to block spam for people who get innundated with the stuff. And some even have ways to block certain numbers!
Its very important that if you are thinking you may have to file a police report, you NEED to keep records of EVERYTHING. That means - save every text message, every email, every voicemail, every everything, and make journals of all contacts with dates, times, and what occured. This will help you muchly to show exactly how and what she is doing rather than trying to remember it all when you file the report.
Sorry she is being so stinky