Debit order after contract cancellation

MTN and *********ly charging its customers unknown amounts, they are number one. I have been a loyal customer for many years, many many years. I started having contracts with them and it was all good. Until they started overcharging me, and when I called in, i never straight or uniform answers. It was either this or that or let me transfer you or whatever.

I decided to cancel my contract, it was near its end anyways so i didnt want to renew. I called in a month before and kept calling just to make sure all is good. My contacted had ended already. To my suprise today, they want to do a debit order on my account and again its a charge that doesnt make sense still like wow.

Kanti you are going to keep overcharging me even after my contract has ended, the question is until when madoda. Until when?