Quote Originally Posted by Astrus View Post
Just to clarify, did you actually buy the boost twice or is it just that one of the other attachments is unique (as in one of the rings, if it gives you free tomestone gear along with the boost) and you already have a copy of it?
Yeah. The level boost book itself, AND the coffer for accessories are both unique. So if you purchase a bard boost before, or say a machnist or ninja boost and have the aiming accessory coffer in your bags still you won't be able to loot from the mailbox.

I'd recommend deleting whatever items you need to and getting the mail if only to get your 500k gil I guess out of it unless customer support actually does grant you a refund, which I'm not sure they will.