Mtn Gamer+ ???

I've just received an sms stating i've been subscribed to MTN gamer+ at R3 per day, i've never once opted in for this product, I have unsubscribed now, but how can I be subscribed to something I never opted in for? If this is a third party subscription how can it be added on my network account without my permission. It's clearly an issue as there are multiple complaints about this but seemingly nothing is being done.