Please give me a link confirming that True the Vote has the telephone numbers. Maybe they purchased only the mules' position info.
Watch the movie. To track the phone pings, they would have to have the identifier. Otherwise, it would be impossible to say that the device went multiple times from the Abrams HQ to the drop boxes. If they have that identifier, they have the phone number. They have the numbers.
This can also be done from the GPS in your car