Equipment Return Post-Cancellation

I keep getting reminders to return equipment since my xfinity cancellation, and they state I have a cable box and cable equipment, but I never had nor used those. You can see from my account I only ever signed up for the internet, and I had my own modem and wifi router. I'm unsure what cable box they are referring to and I really don't want to be charged for something I do not have. I can be reached at my email on file [edit: personal information]

Thanks in advance for any clarity you can provide. (p.s. your agent who handled the cancellation was a GEM and honestly you should hire more of him/give him a raise because if I had not already literally shifted my service, he might have upsold me into staying.)