Closing down of account

I had to contact Nedbank more than 5 times regarding closure of my account. With all this back and forth, I finally concluded with a consultant on the phone that the account has indeed been closed off and that everything had been sorted. A week later, I receive an sms from Nedbank regarding a low balance on the account. I decide to call to enquire, only to find that my account is still open. The consultant I spoke to since said that she will call me with feedback as to why the account is still open when it's supposed to be closed. I haven't received any feedback. Nedbank must note that they will be liable for any charges on that account because it's supposed to be closed