goodluck canceling their service

been trying to cancel the contract for months, emailed and called, I've sold the vehicle months ago and emailed netstar, received automated response, no one has come back, now i received message that they going to hand me to credit bureau. this is plain bullying, spoke to agent and seemed helpful but wanted to sell me a new tracking device immediately as i sold my old car months ago. i also released that the mail adress she gave me is bouncing back, so obviosly the wrong email.

frustrated and i wonder how they would respond in an emergency