Bad Service
I fell behind with my cartrack payments due to the pandemic lockdown in 2020.
So I when things got back to normal I went back to work after retrenchment. 
I started paying off my outstanding balance because I couldn't pay it at once.
Eventualy in December 2021 could afford to pay up my outstanding balance of which cartrack offered me a discount on.
We made arrangements and I settled with the amount we agreed on and payed in full.

And been paying my monthly installment.
two months later March 2022.
Now cartrack is calling and saying that I owe them.
An outstanding balance. 
The outstanding balance is now the discount I got from them.
How I this possible?