Cell C is a no help, no assistance company!!!

After correspondence with one of Cell C's employees and receiving a settlement letter from the employee, the legal department sends me an sms stating that in order to obtain a settlement letter I need to contact the legal department of Cell C. After sending them a email requesting a settlement letter I have gotten no response what so ever!!! This issue is because of their accounts department that haven't done their job correctly and never could assist!!! And after they've sent me a statement that shows I'm in credit with them I still needed to pay them, because there is no one willing to assist or walk the extra mile! And they haven't remove the default and they've listed the default with experian as well now! It is already been 13 working days and no change has been made to my credit record!!