Nightmare Experience - Cell C

Pathetic.... So about 10 years ago I took out a cell phone account on my name for my wife. The debit order got deducted for 10 years from her personal bank account. My wife decided to early upgrade and ever since the upgrade it has been an absolute mess!!! For some reason Cell C defaulted back to an old bank account (closed for 6 years) of mine. I myself do not do business with Cell C, so I do not know where they got the bank account details. We tried to change these debit order details back to my wife's bank account, this is not allowed anymore due to the contract being in my name. Tried now for three months to change the bank account details to my correct banking details without success. Went in to shops/ e-mailed / phoned you name it you cannot get anybody to assist. Pulling my credit report at the end of this month I see Cell C now submitted this account as "missed payment", obviously affecting my credit score negatively. Hopefully turning to HelloPeter can now help me resolve this issue? Next step, other social media... and then perhaps a billboard as this seems to work best. Dealing with Cell C was probably the worst experience of my lifetime!