Frankly, the ad says "Built-in GPS". And nothing more. And it isn't a lie either as the phone does have GPS, built-in. Just because you can't do with the GPS what you'd like to do with it, doesn't mean VZW is lying.
Although Penguin is being a little difficult, I can't say I disagree. If GPS is such an important feature, why not take an extra 2 minutes with the rep to verify that both the GPS hardware and software necessary to conduct the important GPS tasks you need, are available?
You can't rely on a print ad all the time you have to do a little bit of work for yourself. Most of these ads have a "Not responsible for typographical errors" footnote somewhere anyway.
Bottom line. If there is a product feature that is a requirement for you, might be a good idea to see if the product has that feature BEFORE you buy it. Not after. And as always, get it in writing.