Over charging

So I have a contract with vodacom however my debit date was set with them for the second of every month due to my salary being the first of every month so on this morning I notice my debit have not gone off my account I then called vodacom to ask as to why my debit never went off the lady then told me it did go off on the 1 April double check on my account as my salary was paid in on the 1 April at 4:20 but didn't not see and debit order from my bank statement I then told please load that debit as you guys have not debit my account she then transfer me to a very arrogant consultant that advise me that they are gona charge me a R100. 88 for an extra debit order I ask him why as it is not my fault and that he need to check and see that my debit is for the 2sec of every month and that vodacom didn't debit from my account he told that it not there fault and that he have to follow instructions I then ask we're can I send my bank statement as proof there is enough funds in my account since the 1 of April until now and that there was not even an attempted debit from vodacom he just told me that policy phone our legal department if u have any queries I then ask him to get some 1 to speak to and he just drop the call on me I can't believe that vodacom will do this in time of covid 19 were they say they have cut to half there data but now over charging there contract client to pay it back I mean I need to pay an extra R100. 88 for a debit that did not go off on the 2 April 2020