I doubt stations listen for complaints because there's no place to actually complain to! Have you ever tried to find a contact link on a corporate station's website? There isn't any. And Facebook/Twitter aren't much better. The last two times I brought up HD issues on a Facebook page they either a) deleted my posts or b) blocked me for asking them to fix it. Both times, nothing got done.
It's stupid how they claim no one is listening, yet ignore us when we tell them something is wrong, which proves we're listening. No wonder radio is going down the tubes.
My experience with small town stations or locally owned broadcasters, on the other hand, are much different. They're at least willing to say, "yeah, something's broke and we plan on fixing it, but we don't have the money right now." I've even talked directly to some engineers this way over the years. They're a friendly bunch. I don't doubt the same applies to the corporate stations, they're just behind a massive communications firewall that only accepts praise and adoration, not technical questions.