Bad Service Delivery

I was contacted by Cartrack by telemarketers for the fitment of front facing camera. They have made numerous appointments for fitment but each time cancelled due to stock shortage. I’ve taken off work 4 times for scheduled fitment appointments but cartrack didn’t show for one appointment. They have already put a debit order deduction on my account,but i still have no device fitted to my vehicle. They keep transferring me to management,but nobody answers the phone. And i keep phoning cartrack at my expense to follow up on appointments.