DEBIT ORDER / SIM SWAP

I have a contract with Cellc and I changed my banking details last month. I called through to cell c and I even sent an email to cell c customer service with the new banking details. Mind you, my router has stopped working and I sent it through for repairs. cell c sent me a new router with a new sim card and they requested that I do a sim swap... I called Cellc today to do a Sim Swap and I was assisted by a lady with attitude, her name is Sibongile. she told me that she was unable to assist me because Cell c could not debit my new account, apparently there was a typing error and the branch code was wrong. I asked her why was I not notified that Cell c couldn't debit my account and I have to find out now when I called.. she gave attitude and told me she was unable to assist me because clearly I gave them the wrong banking details and I am confused because the account number is right. I REGRET THE DAY I TOOK THIS CONTRACT, Today its my fault that CELL C couldn't debit my account and they don't even have the audacity to let me know. so disappointed and ANNOYED!!!!!!!!!!!!!!!!!!!!!!!!!