Extra Camera

I purchased a camera in store I already have the 10$ monthly for the 24/7 recording, now I was sent another camera I don’t know why but I called and asked for a return label and was told that I don’t need to return the camera I can use it or not but I wouldn’t be charged for it. This sounds to go to be true the camera is just sitting in the box on the table. I don’t want want to be charged extra if I activate it