MTN Subscriptions

I would like to know as to why I received a message like this just shortly before 10PM last night.

Y'ello. Thank you for subscribing to MTN Gamer+ MoFun at R3.03/day or a lesser amount. 1st day is Free. Visit now http://bit.ly/2FH8v0j. To cancel dial *155#. Call 135 for help. Ts&Cs www.mtn.co.za.

And so I also googled the 155 number to make sure this is not a **** or anything and suprise I am not the first customer to have had this experience with mtn.

I also see when following the prompts of cancelling the subscription - which by the way I had given no one authority to do so - I was already subscribed to another.

So I did cancel both but what is MTN's explanation for this and is there anyway we as the public can take a legal route because Im sure there are thousands more complaining!