Destroying Livelihoods

Destroying peoples Lives! I bought on my TFG Account for R7703 and paid back R9435 on a 6 month interest free agreement in 2022. I Have not bought on that account since, yet have been harassed constantly by TFG and their collections attorneys after being listed with the credit bureau for NOT PAYING MY ACCOUNT..... Can someone else please assist me with the Maths as it seems my calculations are incorrect. BUT IT LOOKS AS THOUGH TFG ACTUALLY OWE ME MONEY. YET THEY TARNISH MY NAME.... Is this not defamation of Character? It also disallows me to get credit anywhere else. Please also bear in mind that I have proof of communication from my side in writing where I have attempted to resolve this issue with no proper response from either TFG or their collections agency Shapiro Shaik Defries and Associates