That's insane! I wonder where they all went???? I'd just keep on the lookout for an email from LSAC about it and they'll give you a refund or a chance to take it on the makeup day.
I mailed my Graduate transcripts from University of Florida and it took 14 days for LSAC to receive them. i was nervous the whole time. so i'm not sure about international transcripts. i would say call their call center and see what happened.