Discovery Insure - Cancellation but still debited - Want refund

I had Discovery Insure for a few months and asked them to add their d-track system. I found their excess a tad on the high side. So i found a new insurer, the decided to cancel before they installed the tracking system in the car. I found a new insurer on the 14th Sep 2018 and sent them an email to cancel for the 25th Sep to be the last day of their cover. On the 25th they still deducted and I called hem to query the cancellation and refund. Had a few calls with people telling me i needed to remove their D-track from my car, but I had not installed it. I called a few ties before trying to get a refund from my bank and block their debit order. That didn't go through as a few weeks had passed since the debit order. I still haven't received my refund.

So Annoyed for the inconvenience.