NO CUSTOMER SERVICE OR WORK ETHIC

I have 2 accounts with creditworx, which I have been paying. I decided to pay off one of the accounts, and called during the month of August to speak to them and get a settlement of R1400. I duly paid the amount. I also stopped the debit order because in my mind the account is settled. I have continued to pay the other account. I am receiving calls from them advising that they need me to pay an additional R500. Which is unfair. You say your calls are recorded so go and listen to the call and speak to the staff member involved. I have spoken to numerous staff who promise to look at the query and come back to me. No one has called back to discuss the query, but they keep calling to do collections. I am so disappointed in their service.