Account handed over even though it's settled

I'm utterly disappointed with Altech Netstar. I wrote a review on Hello Peter in 2016 for the bad experience received from Altech Netsar. Then after I was told by Alvina Mashiane and Denise Comeroden from Altech Netstar that a cancellation/settlement fee is required for an amount of R3 222.00 as the contract was only expiring on the 07/07/2017 as there was 18 months remaining. I then paid the necessary amount to settle my Altech Netstar account and I have emailed the proof of payment to both Denise and Alvine on the 9 November 2016. However, till this day I still receive calls from CredixWorx stating that there is an amount I still owe on Altech Nestar account. I have sent numerous emails to Denise and Alvine enquiring about this, no response or feedback has been received till today. Can someone from Altech Netstar clarify why CreditWorx is calling me regarding n outstanding account and why am I listed as a bad debt and handed over? This is ******ion and harassment and I do not appreciate it.