The obligatory follow-up: I finally received a response from Sony CS yesterday (8 days after my submission of requested info!). The rep included a code but wasn't sure if it would work for the expired offer. Well, the code work and I got $50 credit (which I promptly used).
And I didn't even have to speak with a supervisor!
(Plus, I still have the Sony Classics credit, which I believe is good until December. That's not as valuable to me, as I have the Silk Pagoda DVD which has good formatting from what I looked at so far.)
Just another lesson to not worry so much. (Although I wasn't obsessing, just initially frustrated when I started this thread.)