To be fair to the park, the promotional email makes it pretty clear how to redeem benefits. I have no idea how well it's spelled out anywhere else.
From the email:
That’s great. The issue is that I did not see that published anywhere until this past Monday, after we got back from the park, which was after the second weekend of F&W. This is why I am bitter, it wasn’t advertised on HOW to redeem the offers. I should have though about the kiosks since we live in a kiosk world now, but I didn’t and the park hasn’t advertised it as such until this week.