I wonder if that's actually the case. I'd be willing to bet that the confirmation email they sent you stated in the terms that they are in fact not UA, but are collecting money to act on your behalf. I think it quite likely that nothing they said on the phone actually represented themselves as being United, but was carefully designed to not give cause to think otherwise for a caller that had a preformed state of mind that they were calling United. It wouldn't be that hard to do and train the agents accordingly. Not that this makes it right.