MTNYello Spam-cannot unsubscribe

I have been with MTN easily for about 10 years now. Recently they started spamming me from 'MTNYello' - so I cannot even unsubscribe by reply with a 'stop' message (since the message does not originate from a mobile number).<br> <br> Here is the messages in my inbox that I have not deleted yet:<br> 26 Feb <br> 4 March<br> 13 March<br> 16 March<br> 18 March<br> 19 March<br> 21 March 13:26<br> 21 March 14:22<br> 22 March (there may be more coming in today)<br> <br> Three of the messages on different days say I will be called soon about an LTE sim. Some are about sharing data with others, not paying out of bundle rates... <br> <br> I also got an automated voice call about an LTE sim while I was in a meeting with someone. I had to hang up. Now I dont know what it was gonna say.<br> <br> Seriously, if you want to spam someone, at least have the decency to use email. At least then someone can read it at their own timing.<br> <br> I am NOT going to spend 1 hour with their call center to find out how to unsubscribe. F off, or I will find another cell network that does not spam me.<br> <br>