Letters of Demand for a Loan that has been settled

I settled my outstanding loan with ABSA in June 2020, but I have been getting letters of demand for the same loan. In December 2021, I received a letter from Jay Manickum and I responded to it, on 22 February 2022, I received another letter from Velile Tinto & Associates on the same issue. This is becoming a nuisance for me and I would like this matter resolved ASAP.