didnt they just ban like almost 1k accounts because of this?. I'm sure they are taking this serious, but they also need to be pretty sure they are taking action against the right people.

At the moment there are no way to "on depost" gil into the guildbank. Hence why a lot in my own guild are sending gil to our guildmaster. We are a rather large guild saving up gil to buy a guildhouse once it comes out in 2.1. I am sure there are other guilds out there doing the same thing.

Going though logs and double checking stuff takes time. Give them some slack and they will try their best to take care of it.