Bad customer service

Matrix has offered to upgrade the unit in my vehicle and i agreed. Now they didn't cancel the old unit in my car and they keep on double billing me, I've tried months to get through to their cancelation department but no one ever answers. I guess it's another way of ******** people's money by double billing thier accounts. They are quick and available to call when signing new customers but never available to attend to customer's complaints. I do not recommend anyone to sign up with them! It's better to go with other better services.