Yes, i have turned to Twitter when I had something to say to a company. I find it easier than sitting on hold or wondering if they got an email. And when you send an email, they tend to just send a form letter back. Making a Public Complaint on Twitter will sometimes grab their attention faster.
Hell, look at what the Motrin Moms did using social media when they were pissed off.
Watch on youtube.com
Michelle also ask about Facebook, but I am not a fan of using FB to get attention. It is to closed off. I think you can get viral attention much faster if needed with Twitter.
I have no If about using Youtube either. Make a video with your complaint and then push it with Twitter, your blog, forums...Youtube can be embedded by anyone and could cause a real stir once you find your target audience to share it.
Now, we also have Google Plus that is very searchable! Oh yes, we will be trying that out I am sure.