It builds up. The player is gonna get cheesed off and it’s likely that they will, understandably, act like they’re cheesed off.
While that is true and just as understandable, to me, as the staffer’s inability to deal with confrontation with irritable/irritating players… you as the player are responsible for your actions here just as you’re, rightly, holding the staffer responsible for their actions.
The best approach is to leave, not to cause more problems. Either the staffer is intentionally ignoring you, or their backlog is so bad that it’s negatively impacting you. Either way, you leave and hope for better elsewhere. Then you come here and bitch about it with your moral superiority intact.

