What does one need to do when a member decides to rob many valuables from the guild storage and then leave without a word? We have rules in our guild regarding how players must conduct themselves when it comes to taking or depositing to the storage, and stealing everything and leaving is definitely a no-no. He's been in the guild for a good while too, so his rank was adequate to access basic storage, so it wasn't a case of picking up some random and having them steal and leave immediately.
I asked all guild members to report him for scamming, as that seemed to be the "closest" thing in the /complain menu, but are there other or different things/channels we can do?
Send a support ticket and a GM will likely refill your storage if they find it a legitimate request.