Help me to resolve this problem

Good even ,on 2014 had credit acc with African bank,amount of R4000 they've been debiting R300 as monthly installment but know they still claim that I still owe them, I've already paid+-R25000 since then,at the beginning of this year my bank nedcor informed me about new popia law meaning I should come and verify my personal details cause the account I was using was old, apparently I've changed the old to new account by February African bank called me telling me that they can't get through my debit I still owe them ,I asked them how come I could owe R4000 for so many years cause I only use that money I've borrowed after all they've been deducting all these year and now they blacklisted me,when I go to the branch for further report since 2014 till 2022 when they scan my information they don't find it so hoping you might help me cause even those blacklisted lawyers when I call them they said Indeed I'm blacklisted but they don't know how I must ask African bank and by that time I was at African bank using the phone that they said they assist me to go through lawyers,I puzzled don't now what to do cause they are pointing each other.