Milking client’s money because of their staff incompetence and errors

I have had an account with standard bank since I was a teenager. I started working in 2018 and I was told to change account because I have an income now. I went to the branch to open a prestige account and close the card I had. Later on in 2020 when I went to the branch to close a revolving loan I had with them, the consultant tells me that my teenage account is still open they accumulating monthly charge of R 20. I told her to log a complaint because how on earth does one person have a teenage account and working class account all in one identity?? If the person at the branch made a mistake and didn’t close the account, why didn’t anyone from standard customer service call me, send emails and alert me about that account? They kept quiet all these years because they want to make money out of me. I will not pay that account because of a branch consultant error. I want that account closed ASAP! If Standard/Stanbic bank does not resolve this in the next month. I am moving my entire profile to another bank. People warm me daily about standard bank and how ridiculous it is that I should move but because I’ve been with them for more than 12 years, I thought I’d be loyal customer. But this is the last straw for me!