STAY AWAY FROM CELL C

I had an account with cell c and settled the account more that a year ago, I have payed the amount of R27 000 , and still I have not received a payed up letter, and the account is still showing as a default on my ITC , I have made numerous calls to Cell c and sent numerous emails but no one is getting back to me regarding this, Cell c has the worst customer service and I will make sure everyone knows about it