Missing channels

I bought Ultimate TV plan 1 year ago that included 185+ channels. It was a 2 year plan, however, last week (1 year since I purchased), some of the channels went missing including Cartoon Network. When I called xfinity last week, they said that channel now belongs to a different plan and I need to pay $10/ month extra to get it. I clarified that I purchased a two year plan and Cartoon Network and few other channels were part of it, so it should not removed. The representative gave me another option to get the basic plan and add few packages that will include all the channels that i had earlier for a lower price. However, after I signed up for this new plan, I realized though Cartoon Network is now added, many other channels that I had previously are missing now.

The question is why channels are getting removed without notifying the customer and also collect same monthly fee. Secondly, what should I do to get the original list of 185+ channels that was agreed as part of the 2 year plan that I bought last year.

Any assistance in this matter is really appreciated.

Thanks!