I've been having the same problem... with the same response from Apple. I have a developer friend that has an app up on the Mac App Store. He's aware of at least three people who purchased and have attempted to write a review (including me) but it never appears or gets "accepted".
The developer contacted apple about this. Apple responded by sending the reviewers here...
http://www.apple.com/support/itunes/
Why iTunes support? Maybe the issue might have to do with the reviewer's account. Or they are in fact just reading from a script. I'm gonna go ahead and post something at iTunes support but have a suspicion I'll just be send back here.
This is all very dissapointing as like any developer, he needs good reviews. Maybe Apple can put a little more into this... seems it would be worth the 30% cut they take.
Anybody?