Cartrack told me that my account is in arrears due to them failing to debit the correct amount for the past 5 months, due to their system error, as a result the arrear amount was R472

Cartrack told me that my account is in arrears due to them failing to debit the correct amount for the past 5 months, due to their system error, as a result the arrear amount was R472.85. They called, sending emails and sms demanding that amount, while we were at that arrear amount, they offered me settlement amount of 40% discount , meaning i was supposed to pay R283,71 instead of R472.85. After paying the discounted amount, they still demand the money that they said is discounted, I really hate this company with my whole heart, I wouldn't refer anyone to this nonsense company.