Overcharging and wrong date for debit order

Telkom is the worst mobile contract , I have two contract with them and my debit order is supposed to be R255 on August they debit order didnt go through, on the 23 September they suspend my line , they say I have to pay the amount immediately R 255 which I did pay on the 23 September after paying they open my line on the 27 September on the same day I call their customer service to do payment arrangement , which we agreed on changing the date to be 15th of every months and we agreed that I will do EFT payments on the last day of the months as it will give the payment 10 days before the debit order. To my suprise on the 30 September they debited R716.00 . I reverse it and after that I pay the R256 by EFT on the 11th of Oct they suspend my line again on the 12th October I call them around 14:06 I speak with the guy on their customer service for 40 minutes and he assure me that at the end of October I have to pay R256.00. To my suprise on the 20 Oct they try to debit and also on the 26 October and that results to bank charge me for failed debit orders now am in errars because of this . I tried to call them with no luck they direct me to whatsapp which is not helpful. My contract numbers are *** and ***. Please help me