Change of ownership without my consent

I couldn't track my car on the App, I called cartrack and one of the agent told me that the ownership of the device/unit has changed to someone else, I informed him that I didn't make any changes, I was told that they will listen to the call and get back to me and no one got back to me. I have been calling a number of times I am not getting help. I am really not happy with the service!!!