CALL CENTRE DIDNT CHANGE DEBIT ORDER AS REQUESTED

In the end of July I phoned customer care to have my debit order changed from the 15th of every month to the 30th. The consultant I spoke to said everything was in order and that my debit order would go off on the 30th of August so that I will have funds in my account when the debit order goes off.. This did not happen. I phoned client care again this morning to follow up and they said nothing was done. The lady I spoke to then said she would lodge a complaint for me - which she did. She said I should wait for them to call back. When they phoned me back I was told that my debit order date has been changed but, they will still deduct my money on the 15th and when the payment bounces back, I must go to the bank to get a stamped statement and submit to Cell C before I get refunded my penalty fee. She was supposed to e-mail me my case number which I never received for the complaint. Now because of Cell C's incompetence, I have to pay penalty fees and go get bank statements from my bank in order for them to help me. I am not satisfied by this. The fault lies with the consultant that did not do as I asked. Now I am the one getting punished. I would like this resolved!!!!