Return unused equipment has wrong serial number

Thank you, When I try to return via link it only gives me the option to return the modem i am using, not the one I want to send back.

Understood, @user_wecxsd. Let's see what's happening, and then we can get you a manual return kit if shipping is your preferred returned method. Please send a direct message to us by clicking the chat icon in the upper right corner of the page, click on the pen and paper icon, then enter “Xfinity Support” in the “To” section. Please include your full name and complete street address.