Wrong Listing for a closed account

I settled and closed my Revolving account with standard bank 3 months ago. i paid the full amount owed to the account and then called ***to have the account closed, the agent told me that it was closed. 3 months down the line i see on all credit bureau it says that i havent paid for this account. This account according to my knowledge was fully paid. On the 17 June 21, i called standard bank and consultant in the complaint department said would close the account remove the amount appearing as owed and he said he would send a letter confirming that i dont owe STD bank and that they made a mistake. today is the evening of 18 June 21 and i still appear on the credit bureau as though i didnt pay my account and i still havent received a letter indicatig that i dont owe STD bank.