I'm not a lawyer, so any advice that may be taken from my post is not fully valid and I should not be held responsible
Legally speaking I'm not sure there IS a case really. Your text is not a work of art exactly, it's just... a text (very nicely said, done and worded, but still...). This means that I don't think there is a copyright to be attached to your text in the FAQ. Moreover even if there was copyright infringement at hand you'd still have to prove you made the FAQ first, so it's pretty much impossible to do that for a website FAQ in the current laws.
In other words given both websites, and without knowing you I have NO means to know which came first and who copied who.
Secondly, there's the issue of 'so what'? It's FAQ not your thesis or anything particularly amazing. Just get over it, and sent a hate mail to the other studio, saying that you're on to them and they should be ashamed that they did this, and link them here (I can attack them quite nicely if they come over!
). But really, it's not worth the trouble I think.
Thirdly, General texts and ideas have this very simple problem: They can be copied WITHOUT actually being copied: An idea can come from several sources and it hardly means that one copied the other (even in industrial cases). This is why PATENTS exist, as opposed to copyright: You can't copyright an idea, but you can patent it so others WILL know about it but will NOT use it commercially. Just google 'apple vs samsung' and you can see how silly this can get.
All the above said and done, I'd be quite annoyed as well. But since I'm a composer, and I sell my art, I'm much more sensitive about my works of art, rather than a simple FAQ! But I'm still very sensitive.
So go after them. Contact them via email, and then via the phone. Bug the *ahem* out of them. Tell them that they should find a way to use their own words for the same thing (because lets face it... most piano teachers do have students from the age of 4-5 or something, so over stretching this a bit, you end up writing 3.5...).