Account paid up!!

I had a Cell C contract that I was paying off, through NDS Credit Management, as per Cell C handing me over. I dutifully paid every month, and then on the 13th of November 2014 I asked for a balance amount owed, which was given to me as R966.34. I pay R200 every month. On the 3rd of March 2015, I asked for confirmation that R166.34 is owed, as logic dictates that 4 months of paying R200 per month is R966.34 - R800 = R166.34. To my surprise, I was told I owe R250. I tried to argue, but finally gave in and was told that all that is owed is R250, so I paid it. One month later, I follow up with NDS Credit Management for my paid up letter, and they tell me that Cell C says I still owe R199. This is absolute nonsense, and I WILL NOT PAY THIS. It is not my fault Cell C uses the services of *********** fools who keep giving me wrong figures. I have all the e-mails, stating that R250 was the final amount. This amount is paid off and I want my paid up letter!!<br> <br> Stop milking me for money that I do not have. This is ******ion. I want my paid up letter. And do not even tell me to lodge a complaint against NDS, because I have, and I was ignored. Sort this out.