Bad accounts system

I called in November to change the debit order date as from December to the 7th of a month. It was confirmed that it was done. I have the telephone conversation on tape. I even paid three of the numbers cash in advance. On the 4th December 2017 the debit order was presented and returned. On 6 December 2017 @ 17h22 i spoke to the person at Vodacom who confirmed that I did the change in time and that Vodacom made a mistake with the debit order. She will request to reverse the charge. I am not happy with the charge of R100 for the returned debit order whilst i am making in time the changes. I request the change in time in the beginning of November 2017 already. Then Vodacom just decided to combine two of the accounts without my permission. i requested several times to split the two accounts. I am not happy always referring backwards and forwards from customer care refer you to accounts, then accounts refer you to customer care. Nobody want to do anything about the situation.