Same thing has happened to me, I just walked into my pirate prison room and the 5 ariel treasure chests I had bought are missing and not in my inventory. I just checked the shop and I can't see the treasure chest pictures either, but there are blank spaces for them.
I had to buy an extra purple slipper chair because the first one I bought didn't appear in my inventory. My credits were reduced, but no purple slipper chair...
Perhaps, but I saw either Grizzly... or Kevin, I think it was Grizzly, he said they'd remove credits/items if they saw you were exploiting multiple accounts for credits/items. So... if it isn't that, then I guess it's a bug.
