Help! Exguild leader ran off with everything!

My buddies and I are new to raiding so we decided to join a raiding guild. Guild leader asked for money and item donations to help the guild. We felt like this would be a good investment so we all deposited money. There was also other guild members who deposited items and gold. About a day later the guild leader sells the guild and takes off with everything. I whispered him to ask him what happened. He informed me that he decided to join a friend's guild instead. I asked him to return my money and return the monies and items of the other guildmates as well. We all feel like we have been scammed. I tried opening a ticket with a GM in game. Is there anything else I can do?