Continued debits after cancellation

After buying one of their units cash, and spending the next 14 months trying to get them to fix the device I opted to cancel my monitoring with them in November and December 2023 (R5k down the drain for a device that worked for only one month). I received very little help from their cancellations department, the first time I got any REAL assistance was in December 2023 after I wrote on Hello Peter. A lady from retentions assisted me in cancelling the monitoring and confirmed it was done. They have subsequently continued to attempt to debit my bank account every month. Last month I took things a step further and cancelled their debit order through my bank. Tell me why I am now being contacted by LGR Incorporated about Netstar arrears when everything was terminated in December 2023?

Backstory: In October 2022 purchased one of their units cash. The device became faulty within the second month, and I spent the next 11 months trying to get this addressed. After numerous calls by me, and numerous promises by them to arrange a technician to see me, one eventually showed up in September 2023 (10 months later). This technician did not fix the problem and I informed Netstar within 3 days of this. I continued to call them throughout October 2023, and when I called in November 2023 they told me I would have to pay for the repair because the device is over a year old. I admit that I am definitely the fool in all of this for believing that they would act with integrity and professionalism purely because they are a large company