Anyone know how to do this?

I saw a previous post on this (http://www.geekzone.co.nz/forums.asp?topicid=138362), which doesn't have an answer...  Turning off voicemail notifications doesn't disable missed calls texts.

I've called the 2D helpdesk, they told me to turn off VM notifications (doesn't work) and (second call) told me to text back to the message with "stop" (which, not surprisingly, doesn't work because the text appears to come from the caller).  I'm a bit over being on hold to not get the right answer, and figured someone here might be able to help :)

Anyone know how to disable this?  Many thanks.