wrong billing

I don't own a car for the last year and half, I did had a citroen and installed tracker and within the same week I was medical unfit to work and lost my work the same week I asked them via emails and calls to remove the tracker and cancel, they said they will come and remove it the next monday and for weeks I emailed and called I sold the cart as it was arranged with new owner to take over the tracker. I don't work for more than a yeart, I had a stroke and am not allowed stay with my kids and don't have anythin and these Norton people keep on sms and email me for a long time. They just waiting there time. They can check at labour department.