I got this information from Etisalat Nigeria and felt to share here on nairaland. It's for customers of Etisalat Nigeria...on how to stop receiving unsolicited texts/calls (which officially, are known as 3rd party marketing texts and calls, because those text messages and calls are mostly from 3rd parties...for marketing purposes).
Now, to opt out of such unsolicited 3rd party texts/calls, simply do a text message
with only this message: STOP and send it to 2442...from your Etisalat line. That's all.
NB: From my experience, when you do that, you'll get an auto response from them that your request will be effected in 24 hours.
Happy sunday.