Terrible service

The worst tracker. My panic button has not been working since the installation. They have been debiting me for for something that has not been working. I requested a cancellation now I’m being told I need to pay a cancellation fee. Why can they not send me my money back for all the months I’ve been paying something I don’t have. I was told I have to pay for a technician to come and view the device. How do they not know that their device does not work and yet debit me every month. I want all my money back an immediate cancellation