Poor service delivery

During December 2022, i received an sms from cell c, indicating that my debit order for contract will be debited earlier before my debit date. Same dsy i called them to not debit before my pension salary pay date. The offivial noted that on their system. They still debited before my pay date. Then the debit order was reversed cause there was no money. The bank charged me R147, of which i was not liable for. I called them, spoke to a different official, and confirmed that i reported that they mustn't debit before my usual debit order date. The official mentioned that they are also not liable for my bank charge of R147, of which is not my fault. They also charged me R70 for my returned debit order. May you kindly help me find out what could i have done to prevent all this charges, cause i signed the contract for the debit of the 31st of each month, knowing that is my pay date. For the past 5years they have been debiting month end with success,only December they de**** earlier, and caused me charges which i cannot afford. Im a pensioner. My details are as follows: Miriam Mlangeni, cell 084 250 9096 Hope u find the above in order