No sim card and debt letters???

I am really tired of asking cell c to stop initiating legal action. i have received emails from Nudebt saying they are taking legal action against me. Firstly this account is fully paid to cell c. secondly i had stopped paying cell c as they had not sent me my sim card. this contract is over. i have received no sim or free minutes. This is my second hellopeter letter. I had 2 calls from cell c telling me they not sure whats gpoing on and they will let me know. this is 2 weeks later. i will address this with consumer complaints commision if this is not resloved by tomorrow. cell c has broken their side of the contract first and now they are threatening me with legal Emails sfter this account is paid.