Unfortunate situation. A few observations, from a very frequent flier on multiple airlines the last 6 year, including the US3:

1.) All of the planes are sold out. UA knows they can do (or not do) whatever they want. Demand is endless. Don't like their customer no-service? Go pound sand and someone else will take your place.

2.) Customer service doesn't make money, so you are officially overhead.

3.) Frequent flier status doesn't mean anything anymore. See #1.

4.) The US3 only do the bare minimum of what they need to do to keep the cash rolling in.

I'm not saying it's right, but it is what it is.