Mix Telematics/ Tracker Useless cancelation department!

Struggle to close account with Mix Telematics. They keep on dropping the phone when I call accounts dep and cancelations does not Pic up their phone. Send them already more then 5emails with t cancelations letter and drey send me mails that they will open a case but not coming back to me. The still sendme invoices and I soldthecr in March 2025 already