Incurring costs on a closed debt

Planet Fitness handed over my account to them and we made an arrangement of R150 p/m. On the 6th April, I emailed one of them to cancel my contract so it stops incurring new costs and that didn't happen. In October, I spoke directly to Planet Fitness and settled my account with them November 25th 2022. Landau Attorneys is still contacting me asking for me to pay and with them doing this, I am now incurring admin fees from them for a debt I settled ! Every consultant I speak to promises to make a note to my account but hours will pass and another call will come in.