Completely nightmare

I am so frustrated with mtn month to month contract, ever since I took this contract 3 months back it has been a nightmare. Different stories every time I contact them. Sales person told me that when I take the contract Ill be paying for remaining days plus the following month next thing they demanding the payment for the month I was told I'm paying for. Fast forward to today I was disconnected and went to pay thinking I'll be reconnected and I was told that because it's a late payment I won't have internet for the whole of October and nothing can be done. Really mtn?