Tracker cancellation Failure

My car was involved in an accident in November 2019 and tracker alerted me at 1am that the car was involved in an accident. Indeed the car was in an accident, it was written off and I instructed tracker to cancel the policy for the tracking unit on the same day as the accident. I was told to pay R899 in feb2020 towards that cancellation. Today, 20 May 2020 I receive a call to say that it was never cancelled, the R899 was the arrears amount. And the policy is in arrears, the policy is left with 4 months and therefore they cannot cancel it. This is day light ******* from Tracker, they were informed that the car was a write off and they informed of the accident. 6 months later they want me to pay for a service they have not been rendering.