They actually answered!

I sent a modified version of the letter below to the nice folks at Tampax and got this note back the very next morning!

"Thanks for contacting us.
I'm sorry you're disappointed with Tampax. Our goal is to produce high quality products that consistently delight our consumers and I regret this wasn't your experience.
We rely on consumer research to help us understand what people want from our products, and as a result, our tampon was designed to be shorter and wider to better fit your body. The improved size and shape, along with the built-in back up skirt, provides better leakage protection than ever before. And we designed the new grip applicator to make insertion easier. Still, I understand you were dissatisfied with our design, and I'm sharing your comments with the rest of our team. Feedback like yours is important to us and will be helpful as we develop new products.

Thanks again for writing.
Tampax Team"

And so I wrote back thusly...

"Thank you for writing back! I really appreciate that you are trying to improve your product, but I think that you should a lesson from the New Coke debacle and leave things as they are. Bring the new design out as a different (new) size while leaving the old size alone.
Thanks again,
Mystery Mommy"

Sheesh. I'm guessing, judging by the quick turn-around on the letter, that I'm not the first person to complain about this. You'd think a company dealing with menstrual flow would know better than to mess with women who are already plenty cranky!