Guild bank theft

We had a player join our guild for about a week. Said he was new to the game and was eager to push content and have a good time. About a week or so goes by and he messages our discord server saying “hey guys I have had alot of fun with you all but some IRL friends on alliance want me to join their guild”. So of course, no worries, we sent him off with good wishes.

We then go and look at our guild bank logs and noticed that he stole 95 top end crit gems and some other mats, then deleted all of us off ID. Him being only a member and being allowed to take out no more than 2 stacks of items; I have no idea how he was able to take all the things that he did. There isn’t any way that we can report the player because we have to right click on their portrait to do so…he is now alliance and not “friends” with any of us. When you go to support and look up a way to “open a ticket” it just tells you how to change the guild bank tab permissions for each rank… Are we just supposed to take the loss and shrug off all those gems? 250g a pop on our server just makes things more of a pain to lose. If anyone has suggestions about what we should do, just let us know.

I have the culprits ID if that helps at all. I have also sent him another friend request to see if he would talk to me about it, but have gotten nothing.