Why are you charging me bank fees for an account that is closed. and Why am i paying for an account that i have closed in 2018

In 2018 my Elite account was in a negative balance and standard bank said if i do not pay they will take me to the lawyers and i manage to paid off and i have asked the standard bank employer to close it because i no longer get money from that account and it was done. Now yesterday when i check my other accounts i see that i have a negative amount 3000 and some odds. If i close an account why are they charging me.