Upset customer about cancellation - Urgent help needed

I phoned Vodacom on 04/12/2020 to inform them that I would like to cancel my line that was due to expire on 03/01/2021. I phoned again on 15/12/2020 and was told that it is still in progress. I then phoned again on 23/12/2020 and was informed that the line was cancelled and I would pay my last installment on 25/01/2021, which is correct. On 01/02/2021, data was loaded on the line, meaning the line was not cancelled as per my request, I then phoned Vodacom again and on 01/02/2021 I was told that cancellation has been logged and I will not be billed on 25/02/2021, which I was billed for any way. I then phoned on 25/02/2021 and was told that the cancellation has still not been done. I requested the cancellation again and also a credit for February as I was incorrectly billed as I requested a cancellation already. I was told that I would receive my credit within 14 working days, which has still not happened. Today 15/03/2021, I phoned Vodacom again to follow up on the credit and was informed that the credit has not been logged and also that the line has still not been cancelled. I am being billed now for end of March as well, eventhough I requested the cancellation on time and as per the Vodacom regulations. I need help to make sure that I receive my credit and that the line has now been cancelled in full. I was not negligent on my side and I feel that Vodacom's service consultants have now caused me to lose money and did not do their job. I have asked to speak to a supervisor and this has not also happened. I need help please to get my money back that I am due.