How does NCR works

Morning, I had an account with sleepmaster for 12 months In February this year I decided to settle my account I was surprised when they told me to pay the whole amount Remaining including the insurance for the bed that I took from them...... I asked if the insurance would be covering me for the remaining months until 4 months and they said "NO", I payed them R3000 which was left but they're still demanding me to pay more And that is affecting my credit rating.... They want to take me to court