Many of the issues concerning communications is due to the fact that PSO2 Global is ultimately managed two different teams; Sega of Japan and ESTsoft.
ESTsoft is the company the GMs work for, the one who handle social media, livestreams, English announcements, etc. That said, like many people correctly guessed here, they have very little power on lots of things since ultimately its Sega of Japan who runs the game's servers, pushes out updates, creates and implements content and carries out investigations on many matters; hence the reason JP and Global BOTH had their player shops close at the same time as the exploits had begun to appear on the Japanese version as well (also, the team managing the Global version is the SAME team that manages the JP version).
Now mind you, ESTsoft's responsibility is also to communicate with Sega of Japan on many matters but, like the GMs have stated multiple times, there's no guarantee that suggestions or appeals will be accepted by them.
The game's age and programming also plays a huge role too. We don't know the specifics on what tools the Japanese team have available to them and all that mind you, but the best of putting things is.. under-the-hood, PSO2 is more of a badly programmed single player game with multiplayer support when you consider the way in which nearly 80% of the game runs client-side! On JP, a few hackers could actually make themselves GMs and teleport players all over the place and summon bosses to the lobby and so on. As such things like restoring lost items, seeing in-game item purchase history and so on may very well be things which the game's server simply wasn't programmed to keep track of and the game may very well not have been programmed to deal with bots all that well. The only reason PSO2 wasn't hacked back in the day was due its obscurity outside of Japan; the Global release had in a sense made the game a bit more mainstream and in turn... a bigger target for those with other motives.
Taking all that into account.... I feel there's very little that can be done. At the very least, with New Genesis around the corner there's a small chance some of the issues PSO2's code had might be dealt with but I really wouldn't count on it...