MTN unwanted subscription. *****ing my money.

I received this SMS today :

“Yello! Thank you for subscribing to GameWin at R2/day. 1st day is Free. Play now http://bit.ly/2EuGFRw . To cancel dial *464*970#. Call 135 for help. Ts&Cs mtn.co.za”

I never subscribed to this.

How can MTN subscribe me to a service/game I have never heard of before. Surely it is ******* to take my money for something I did not ask for or signed up for.

I went through the contract I signed and nowhere does it say anything about subscription to services.

Six months to go and goodbye MTN