So called unsettled loan

In the year 2021 around May/July I went into Airport mall Capitec Bank to pay off my outstanding loans. The agent paid it up leaving me with a balance of 0.01c she said I can do a transfer on the app to clear that, I've done that and then as months went by it accumulated again to over R200, paid that again and this loan was still visible. I then went into the branch thrice where a wonderful lady Nastashja assisted and called in where they confirmed that the agent made an issue on her end and did not settle it as an AdHoc payment. The agent no longer works for Capitec Bank. HOW IS THIS MY problem when they hired someone unskilled to do the job??? I am sorry I am now being treatened by Capitec Bank that if I don't pay R700 I will be listed as a bad payer. If this is not settled I am going to sue Capitec Bank and get my lawyer involved. Sort this out as soon as possible!!!