Poor service on faulty unit

Terrible service for faulty units. Paid upfront for 3 years, tracking unit has been giving problems from the get go (showing that it's at the wrong address and not recording some trips). 1st time I logged this issue they sent a tech, 2nd time they said it's software related, 3rd time no one even got back to me, 4th time (today) they said I should bring it into their service center, which I did and kept asking them to change the unit as obviously it's faulty but was told NO device was installed in a place that couldn't receive signal and they have changed that... Not even an hour after leaving there Issue came back and showed vehicle being in a different location to were it actually was, so called the service center to let them know and they said they'll get back to me. It is now end of business still 'waiting'. Am now at my wits end and Will log another fault on the app and wait. Terrible Terrible after care service... What's the use of having a tracker that doesn't know the location of your vehicle.