Don't think that's quite legal. You have to notify someone that you want their product. Not that you don't want it. They put it on my units and they will hear from a lawyer.
Better to call to opt out then wait for them to install. They installed a DCU on my AC while I was out of town on vacation. They screwed a box to siding, cut a hole in my AC and wire the box to my compressor without my permission even though their website states the homeowner must sign a service agreement prior to hardware installation. I was not notified that anyone was coming that day and I did not sign up. I called the next day I returned to have it removed. They wanted to schedule an appointment to have it removed even though they didn't schedule to install. They removed the unit leaving holes in my siding.