It was by mail in the packet from Price--first I got an envelope from USC in general with no mention of money, then one from the MPP program a few days later. It might be different outside the U.S., though. I never got an email.
I absolutely didn't send high school transcripts, and I got in, so don't worry.
I feel for you, though. I decided last week that I hadn't applied for the Dean's scholarship, although I had, because of an old .pdf I found on the website.
Probably they aren't lying to you about a response being forthcoming