I have a question ... I called VZW and made arrangements to send me a S7, and its +$8 per month on my bill as long as i send them my device and its in working and not damaged. I currently have an S6 But i have an old S3 that still works its just not connected anymore. Can i activate this on my line and send that in as my device trade? Or will they see the change and call me out on it? Id rather keep the S6 as my backup if its possible, obviously.