Before all else, why doesn't gree try out having customer service? Maybe if people didn't have to wait 3 weeks or longer for an account transfer, or when buying gems and Google charges your card but gree doesn't give you any gems or any other number of issues that happen every day. Its hard to play a game when you know that when something goes wrong, you know that it will probably never even be addressed because gree can't be bothered with it.
Get a customer service department. If you actually have one, double its size. Your current system is unacceptable.