I've been going through this recently quite a bit. Reporting stuff is a waste of time, except for entertainment purposes.
I've reported all sorts of things. In nearly every single case, they say they cannot do anything. Even when there's a fake DropBox app "by" "@Microsoft". In that case, the CSR told me to try re-installing the app, that it worked for him. Zero understanding of the issue.
I've found a fake Windows Update on the Store. Reporting it got a generic response, until I emailed the MS security folks. Then it was removed in a few minutes. Meanwhile, they suggest I "Leave a review" or email the developer. Idiotic.
Netflix went back and forth with MS at least 3 times. Amazon had issues as well. Other ISVs tell me they can simply not get MS to be responsive about things.
Disney was the funniest response. Despite being a major Store publisher, there's all sorts of fake Disney stuff online. When I spoke to the Disney Store about it, the final suggestion was "don't go on it [the Windows Store]". Neato.
It's obvious MS is just padding the app numbers and no review is actually happening. It's a shame, since it undermines all the work; the Windows Store is a joke even with casual users. (Like even meeting random people on a plane and asking.) I emailed Satya. I emailed the GM of the Store. I emailed the Dev evangelist pushing the "let's pay people in third world countries 4 months salary for publishing 20 shitty wrap-a-webpage apps" program. No replies.
Here's a gallery of some gems: http://imgur.com/a/xvqZg#0
But nothing beats this awesomeness: http://imgur.com/fLOWMI4
I really hope they enable an Android compat layer. Even if it's slow, A: tons of random utility apps will be available, B: MS can enforce some quality instead of quantity.
I find it hard to believe MS isn't aware of these issues, unless no one actually uses it (Win10 makes it more in-your-face, though). Someone must have a bonus that's tied to "published app count". Neither Apple nor Google have these issues. The Store is worse than the Android Marketplace was.