Here's what they said:

Dear Frank,

Of course we want to hear from you and are sorry that you were unable to find our e-mail address on our website. I am doing some checking now into how we can make our contact information more accessible on the website.

In the interim, please let me know in what way we may be of assistance. We look forward to hearing from you.
And here is their email: Kodak Professional Traditional <kprotraditional@kodak.com>

My only word of advice is to be polite, articulate, and professional. And to the point. If you come off as a raving loon then your comments won't be taken seriously.

The discontinuation of 5x7 color neg and 8x10 Porta 400 prompted me to complain. It would be swell if they got a couple hundred more complaints about the same topic.