It doesn't make sense to build a relationship with a manufacturer to only do a collection once. Maybe not exactly the same pieces, but I would bet on more items (the same or different) releasing in the future.
I would seriously consider sending a PM or email before you lose your mind. I have sent several emails regarding my orders that haven't been shipped and to my surprise, they were delivered today. Might be a glitch in the matrix, but don't wait until they can't fix it before you send an email.