In my opinion, I think it'll be helpful to have a feature where you write down your queries so that any online staffs can review and respond to it. Sure there will be a spam, but spams will always happen anywhere. It may not be prevented 100% but it can be lessen. By only allowing to send every 3 minutes just like the report system.
Before they can send their queries, there will be a notification that pops up to state all in one message.
Maybe it can also have a FAQ list where they can tap/click and the answer will be sent by an NPC server
Graalonline Era iPhone since 2011.