Cartrack does not cancel account

I had a tracker installed on my car in Nov/Dec 2018. In November 2022 I traded that car in for a new car and called Cartrack to cancel my debit order and subscription.

Come February 2023, I see that they continued debiting my account and when I sent them a mail asking for them to reverse and refund those funds, I was told that I had only canceled my roadside assistance, not my main tracking account.

I told them to cancel it immediately via that email conversation dated 06 February 2023. They then called me on my cellphone a few days later and told me that I needed to provide them with thirty days' notice of cancellation. I asked them for what good reason, especially as I had canceled it with them back in November.

I canceled all debit orders on my account at the bank, and at the end February I saw that they had managed to get a debit done on my account, which I reversed. Now they have sent me a letter of demand to make payment on this account.

I had the exact same experience on one of my previous cars, on which they refused to accept cancellation and continued debiting my account.