DVR recordings being removed

I had the final 3 seasons of The Big Bang Theory on my DVR. Comcast has deleted them over the last month. I did not delete them. Comcast is pushing us to leave their service. Why pay 20 dollars a month for a DVR and recorder things, if Comcast is going to decide what stays on the DVR and what doesn't. They have also removed the last season of Young Sheldon and The Neighborhood.  We liked to watch these shows on the weekends. Now we dont have them to watch, since Comcast decided to delete them. No, we haven't  changed our recording settings. And after 3 hours on  the phone with 2 different techs, I gave up getting any answers.