CELL C CONTRACT CLOSED MANY YEARS AGO BUT STILL SHOWING AS ACTIVE ON THE ITC AND AFFECTING MY CREDIT SCORE

I had three contracts with Cell c and i have settled all of them in 2018 but it still refflects as active on my credit score. I have been calling the legal department but they are not even picking up calls. It very frustrating because this wrong information is affecting my credit score negatively. I need this to be corrected Urgently please . my number is ***