Cannot turn off "missed me" sms notification under any circumstances

[amh2012]

I have tried everything- I changed the notification ringtone (under phone settings) to silent, i changed the text message ringtone (under text message settings) to one of my own creation, I tried abandoning my own ringtone and setting it to a droid tone (tinkerbell), but even still- the tone "missed me" plays in addition to whatever tone is set. I cannot get rid of it! Even if I change the text message notification to silent, "missed me" still plays when a text message is received. I also tried restoring default settings and restarting my phone, and nothing works. The only thing that prevents that sound from playing is silencing the entire phone completely. What can I do?