A total lack of service and poor admin on tracking devices

If I could give 0 stars I would, I received an exorbitant annual increase on my policy, (20 + %) called the call centre to see if they could reduce the increase as it was excessive, was told there is nothing they can do and I should reduce cover or increase excess if I want to pay less. Due to the total lack of service or willingness to engage on a policy with no claims at all, I activated a policy with another insurer. On calling to cancel, I was then offered a reduced premium by Discovery, too little too late. I then received a threatening email that I would be charged a large sum of money as a penalty if I don't remove the standalone DQ tracking device from my vehicle before cancelling. Funny thing is Discovery themselves (or appointed representative) removed this tracking device a year ago as it was draining my vehicles battery. I replaced it with a different sensor and called Discovery to confirm the changes at the time - they seem to have recorded it as a repair, not a removal. I sent an email stating as such, and received a response that their records don't show a removal. I don't have the device and just wish to cancel the policy. Just all round terrible service. Seems it is going to be an admin nightmare to get out of this policy without being charged ridiculous penalties on a tracking device you forced me to install, caused issues with my vehicle, you then removed at my request and are now telling me is still in my vehicle. Honestly, it is a tracking device, you should know where it is or how are you monitoring my vehicle location?