Sorry to hear about the OPs experience.
UA seems to be really missing the mark of late. The impression we are getting is that transactional beats loyalty, and there is an over-riding quest for marginal revenue.
If this is the way that UA is implementing this strategy, they really are blowing it. The people willing to pay for these optional services don't know that UA systems are awful, they have to check seat maps daily, and to make a stink with the Gate Agent if things don't seem quite right.
Good luck getting someone to pay again after being treated this way....