Failure of cancellation

Shortly after taking out insurance on my vehicle, I had a tracker installed in my car. Although after finding out that the tracker does not work the way I thought it did, I then contacted the insurance and requested that it be cancelled. I know that I entered into a 36 month contract, or something like that and was willing to pay the settlement amount. They assured me it would be cancelled, although no extra monies was ever deducted from my account, so I thought that maybe it wouldn't be necessary, seeing as I had the tracker for less than a month.<br> <br> Here we are, a year and a half later and I receive an email from the Tracking company with an invoice to pay? Apparently nobody never cancelled the tracker and now I've got to pay that invoice as well as the settling amount.<br> <br> Why not just do the job that you're being paid to do??