Delayed Cancellation

I'm almost loosing my mind because non-ending calls from Netstar. I have three active Netstar trackers, the lastest one prepaid for a new car. The other two cars were sold in Oct 2024/ Feb 2025 and I had subsequently asked Netstar to deactivate the trackers and issue an invoice for early termination fees. Its been months now that I'm sitting with this unresolved issue, and Netstar attempting to debit my bank accounts for the monthly subscription. I need confirmation of cancellation and an invoice so that I can close the two trackers and remain with the prepaid one. Also I authorised a debit order from my FNB account but for some reason Netstar switched to my Capitec account without any authorization from me.