I had the same problem with my gift set. Scheduled to ship on the 11th of June but when the 11th came, it was still un-shipped. I called them and discovered they had outsold their number of copies in pre-orders. A couple of hoops later I had them sending me the books two day shipping free, as separate books instead of the gift set, at the pre-order price of the gift set. Being in middle of California, they arrived here the next day.
So If you're still having problems getting your gift set, I advise asking them to get the three books instead, if you don't mind not getting a slipcase.