Cell C Direct Debit Failure | ***

i have been having issues that cell c is not resolving. i changes my bank detail and gave the my new bank account for debit order to go through. what they are doing is still debiting the old account that i am no longer using and charging me for returned debits. the charges are accumulating and they want me to pay them. I have all the proof of communication with them and still they are not resolving the issue. i have been paying my cell c account by EFT but still they put it on my credit score and say i am owing them. I even sent them proof of payment and the last call i made, i demined them to cancel the old bank details that they have on the system as am paying by eft. all my request at cell c fall on deaf ears. now my credit score has been affected and they are still not removing the amount and still continuing to debit the old account. I have been speaking or communicating with the lady called Kelly Stubb (Customer Service Assistant) and there is nothing, she is helping me with, but just same routine messages. And she never bothers to call me, always refers me to customer service center and still all of them gives me the same answer when i call