FORCED IN PAYING

I had a loan with the African bank an amount of R15 000. I then defaulted from my payments but paid the account in full when African bank offered me a settlement discount. I paid and African bank provided me with a paid up letter. I since July I have been receiving phone calls every day from Credit works demanding that I must pay them interest on the loan and that I was supposed to pay Credit worx and not African bank. On the 3/10/2015 I received a call from Credit Worx from Ms Shumani Sintumule she was so rude I thoughts she was going to jump out from the other side of the phone and slap me. I cannot accept this behaviour. I have paid the people I have a contract with they even updated my ITC. Why is Creditworx forcing me to pay them. Can they please provide me with a contract that I have with the. Can you provide me with your official link to your website? Please stop harassing me.