Some channels not available on Tivo

I am using a Tvio with an M-card.  Some time ago I lost the HD versions of a couple of channels, FS2 (1209) and Sundance (1440).  When I go to those channels it says, "Channel not available". The SD versions of those channels work and the HD version works on stream.  When I contacted Xfinity at the time they said it was a problem with my Tivo.
I have recently swapped out to a different Tivo unit and the issue remained.  I then swapped to a new M-card.  That didn't help either.  When I go to the channel strength meter, those channels are not available to test.  They are not there on the cable card test, either.
I was on chat with an agent for over an hour and a half today and the agent left the chat with no warning and I had to start over with a new agent.  The new agent ran some tests and said this, "As we have done all the steps from our end, I'll now be getting this escalated to our Higher Fix Channels Expert  Team , They;re a group of Specialized Technicians who works on this error  issues on channels remotely, they'll check everything remotely and get it fixed, usually it takes 24 hours for them to call you back however I'll inform them to call you on priority within few minutes."
Someone called within a few minutes, but soon after I explained the problem the line went dead.  I never heard back.
Is this an issue that can be resolved.  I am not getting the service I am paying for.