Settled cell c contract - affecting credit score

I had a cell c contract that I opened 2019. This contract accumulated arrears of R4400 and was handed over to attorneys.(ssda attorneys) I settled this account on the 12/01/2022 and was told that I would receive a paid up letter within 21days. I still have not received the paid up letter after calling numerous times. This cell c account that is still showing on credit buro with arrears is affecting my credit score. I am unable to get hold of cell c and the attorneys that I was dealing with have tried to contact them and send emails but no body can assist. Please help