FNB charging on settled accounts

How is this possible that after settling an account with FNB, they take you to the lawyers for amount that's outstanding. After I complained here on Hello Petter and was given my settlement amount and I paid it same day in November 2020, only to receive calls this week saying my account is in arrears. How is that possible?

How do you settle an account and still be sent messages about your account being handed over. Now this is ruining my name. FNB is not being Profesional here and I need this to be sorted out.

I settled my account and sent the email to Ms Seabi on November 2020.