Once you start escalating, you create a confrontation, and you’re much, much less likely to get what you want. You were entitled to a refund or a reroute on UA flights. You got exactly what you were entitled to, rather than what you wanted. In the future, if someone turns down your request, be polite and hang up and call again. As soon as you ask for a supervisor, you guarantee that negative notes will be written into your record — the supervisor has to know why you escalated, after all — and you pretty much ensure you will only get what you’re entitled to.