there was a comcast system wide issue that affected many people and has been posted here. You need to delete and then recreate your series recordings, if that does not fix the issue call comcast for a box refresh.
I seriously doubt you can get a credit for it, but you can always try.
I just returned from a few days out of town and went to watch some of my scheduled recordings. I looked, and none of them were recorded. So, I looked in my series list only to find that there were none. Looking in the history, I could see that they were all "canceled by the system." So, I'm obviously angry that I didn't get any of my shows. Why did they all get canceled without any interaction from me? Are there any remedies for this (or at least a credit to my bill)?