Selling back my unused ring devices to ring

I have two ring accounts - for home and business. I had bought more devices than I needed. Unfortunately, I had to go with the electricians' schedule in order to install the ones that I needed. And in the process, the return date for the unused ones is way gone. For almost all of them the boxes were not open at all. Is it possible to sell these unused devices back to ring so they can sell them as "certified refurbised" or I am on my own and just have to sell them on ebay or other websites. Please anyone with ideas/suggestions