Unsubscribe me from Mtnplay!

I unwillingly subscribed to the MTN Play service 'Ask the Sangoma'. Without stating when or howmuch this would cost, MTN have automatically deducted money from my airtime. This will continue until I unsubscribe from the service.
I have trawled the MTN website and my phone options in an attempt to find out how to unsubscribe from this service to no avail. The absence of this information has led me to believe that this is a deliberate scheme set up by MTN and as a customer I feel swindled.
How can MTN offer this service without declaring the cost of it and how to unsubscribe up front?!


Please unsubscribe me from the service in box messages and stop deducting my air time,I get free smses for weather/lotto daily 4rm my BBM.if u dnt unsubscribe me then I wil have no choice bt to change my sim card to another network coz I nw I have to by airtym nd make sure its al used same time to avoid u guys 4rm deducting it... Thankx...