No permission request for unwanted subscription

It's really annoying when these big corporates are always leeching and wanting a pound of flesh from consumers. I got an SMS now out of nowhere indicating that I've been successfully subscribed to MTN Gamer+ at R3.03 per day. I had to now dial the *155# to unsubscribe. MTN, please don't even bother trying to explain your leeching ways out of it because it is what it is. There is no way to correct this ********* business practices.