I have been adamant in ignoring this girl for weeks. She's not really stable (hence I don't want to keep contact with her) so she isn't getting the message. I've even asked that my other friends not bring me up because I don't want indirect communication with her either.

I'm not sure text message systems can be disabled on my phone. My cell phone carrier prides itself on free unlimited text messages on every plan, so I can't think enough people ask to have it disabled since they're free. The company even sends texts through the phone to let me know when the bill is due, etc.

Apparently I can file a police report, which will hopefully be our last resort, if I can't prevent contact by myself/with the phone company.