Telkom Debits Do Not Make Sense!!!

I was wrongfully debited on my Telkom subscription as they claim that I missed a debit date which I had not missed. I contacted the customer service on numerous occasions before my next debit date to rectify this but I got no assistance. I even sent through my banking statement to the customer consultant to show them that I had money in my account for them to make the debit hence why I do not understand why they charging me money for a "failed debit order". They deducted the money end of Feb, I just got the March invoice and it still shows that I owe them the amount that they deducted as well as my subscription fee inflating the amount further to something that I do not owe them. I am very disappointed in Telkom and their customer service because I always make payment and have never missed a payment there I do not know why suddenly they are failing to do the right thing. I cannot wait for my subscription term to finish so I can be done with the service provider.