I e-mailed support at Denon USA - no response.
I called support at Denon USA and was told they'd get back to me (I even asked "what if you don't?", and was assured he would) - no response.
I e-mailed again, including everyone's e-mail address I could find, stating my displeasure, and turned on "read receipt" on the e-mail. I got an answer!

Dear John,
Please use the following link for your convenience.
[Link: oldusa.denon.com]