Supersonic/MTN weak communication

I was a customer with Supersonic through a promotion with MTN and I received poor communication from and they never told communicated changes to price or promotions to me neither did they communicate that even though the promotion said "month-to-month" and "cancel anytime" I'd have to pay back a 12 month claw back fee of R899, and now they said the promotion was only for 6 months and due to changes to the pricing which wasn't communicated to me I owe them R1876 suddenly. They never communicated with me and never responded to my emails or whatsapps to them.