You are better off getting a https://www.dropbox.com/ or another service for recordings.
I did an online chat with Comcast and the rep said that they do keep video recordings and to call a number. I did and was transferred twice, the last person said that they don't but to call back in regular hours to confirm.
So I did another online chat which took some time and that rep said that he put in a ticket for a comcast rep to call me. It has been days and I haven't heard anything.