I see what you are referring to. It's the "Report to MOderator" within the PM functon to report abusive PMs.
Sorry but I did not write the software saying that a moderator would always get back in touch in response to reports. I've never even seen it until I sent myself a PM report. I'll have to add it to the "do list" to change that, if I can figure out how.
I care about what happens on the forum and obvious abuses of PM but there is no way I can force people to resolve their differences of opinions within PM. Refusals to stop inflammatory posts in threads have and will result in closed threads and sometimes temporary gags to cool people off. I do want to know if people continue arguing on forum threads while refusing all efforts to take it privately as that is evidence of troublemaking. But if they clam up on the forum and refuse to talk about it privately, there is nothing any mod can do to force resolution between people.