Last week or so I received the invitation for Subeautique and redeemed it. At that point, I was able to access items in the shop. Today I went there from the News link and purchased an item (there were only two items for sale), and now it's saying that I don't have an invitation and cannot access the store? I don't really know how to go about reporting this because I can't prove that I had the invitation since I did redeem it :(

Invites are similar to currency. While you buy items with sP, you need an invitation for each item you buy. So if you buy an item, one invitation disappears. It's sort of like an invitation to purchase a single item, and once that single item is purchased you need to find/buy another invitation to gain access to the shop again. You don't have to buy an item right away and invitations won't disappear without a purchase, but you need one redeemed if you want to get in there. ... It can be confusing and annoying.

I had no idea, dang. That was the first time I had ever gotten an invite and I played for a while back in 2010. Thank you for clearing this up!

It was changed a while back because staff felt the higher end items needed to be more limited. You used to not need an invite. No problem !