FNB Current account bad service

I've been struggling to ge assitance at FNB call cetre and being transferred from pillor to post regarding an outstanding amount of my cheque account which I paid up in 2019 via the company they handed me over to. I never got a paid up letter because I waa told the bank is busy processing the file only for them to open my account again and being today I have an outstanding payment. I'm frustrated because the payment is reflecting but no one can tell me why I'm handed over when I haven't banked with them over 3 yeara now.