There are at least half a dozen people posting in different threads here about this "ABCXYZ is not part of your subscription" problem. You can read what people have said and the official Comcast reply in this thread: http://forums.comcast.com/t5/XfinityTV-Website/ABC-is-not-a-part-of-your-subscriptions/m-p/1989101#M30072 if ComcastJoe or ComcastDaniel don't answer you in this thread you may want to private message them and see if you can have them look at your problem.
Just FYI, you are the second person posting here about a problem specifically with "Orphan Black".
- Norm