Unable to remove sold car from Cartrack Fleet Account

My company has a Cartrack Fleet account. We sold a vehicle on 2 Oct 2023, on 10 Oct 2023 I called the call centre to have the car removed, I was told to complete a form and email it to them, which I did on the same day. The car remained on our account. Since that day I called the call centre several times, emailed the completed commercial cancellation form to all the addresses provided, at one time we had the call centre lady hold on until she confirmed that she received it, yet today it is 26 Dec 2023, more than two months later and the car remains on our account. It seems impossible to remove a car from a Cartrack account...