This was the unfortunate assumption that George Vaccaro made when dealing with Verizon. His ordeal is chronicled in his blog. That was three years ago, and resulted in Verizon refunding his money and promising to "supplement the reference material used by [their] representatives" to correctly state the rate as $0.002 dollars and not 0.002 cents. Evidently, nothing has changed, and now AT&T is quoting the cents figure. Fortunately for the world, Adam Savage of Mythbusters (via his Twitter, @donttrythis) has evidently run into a suspiciously similar problem, possibly with an additional but similar confusion as to the difference between kilobytes and bytes.
The purpose of this (supposedly unintentional) tactic seems blatantly obvious, and it works: most customers won't notice the discrepancy, and will just pay the rates. The occasional customer (the aforementioned George Vaccaro, a second case he mentioned in one peterS, and now Adam Savage) notices, and after some wrestling, they quietly reverse the charges with assurances that he documentation will be corrected. They of course never do update the documentation, because that would keep them from raking in massive profits from those who don't notice the discrepancy.
Now, as someone who has a bit more presence than some random customer with a blog, can Adam set this right once and for all, and get the phone companies to finally change their ways? Considering their history, I'm not holding my breath. But here's hoping. I would allow myself to be terribly cliché, but questioning shady, deceptive business practices on one hand and questioning commonly held but uncorroborated public conceptions just aren't close enough for me to swing it.