Mtn contract

I am really, really disappointed with MTN, I bought sim card data last in March and I cancelled the contract on the 7th day, I didn't use their data... But now the problem is they expect me to pay R2000 and something for the contract I canceled on time and never used any data

And the worse part is when trying to call them they don't answer and when you go to their shops they tell you to call them.