MTN the biggest ****

On 11 May, I called MTN to cancel my data contract with them as I was moving to get unlimited fibre with them. It was obvious that I would not need an extra 80G for out of fibre use. I earn a SASSA grant so have not much moving around. The guy offered me 10G for R45 which I agreed to but never happened. . Since then MTN continues to debit my account and blocks use of the phone when they deem fit. I honestly cannot afford all these costs as if I run a business. What do I do with all this data and fibre? When I call them, they play hide and seek.