Threatened by Amber Connect with out even explaining!

We have had this tracker service for the last 5-6 years.

We have lost 2 vehicles due to accidents. They were written off. When the one bakkie was written off I requested the service to be cancelled. They said the contract is another year. This was last year June. Now I want to cancel it with the other vehicle that also was written off and I receive a call from a Mitsi/ Mutsu to say that I must pay a cancellation fee or Ill hear from their lawyers as I will be handed over. I asked for a letter or an email to explain why I must pay for a service I have not been using for 2 years. Surely they can accommodate their customers with these issues. I will not ever recommend them to anyone. Even to get into contact with customer service is a one star!