MTN INCORRECT_OVER BILLING

I recently started a contract with MTN really hoping it will be smooth sailing, not having to worry about huge unexpected bills or having to spend 1000s of hours trying to explain something from a customers viewpoint (as was my experience with another service provider and the reason I moved to MTN). I mean really, do I(customer) need a lawyer just to get something as simple as a cellphone contract???

My request was CLEAR and I made the effort by going to an MTN shop in person to avoid any misunderstanding.

I am being billed DOUBLE the amount that was requested and agreed upon. The contract I app**** for should be R1449 pm x 24 I regularly check my balances and have not gone over any limit since I received my contract. WHY AM I BEING BILLED OVER R3000!!??? for a cellphone contract? This is insane!