How can I claim the reimburse of my money? Newsstand.

I have bought the July/August issue of "LawPractice" Magazine at the Newsstand in the App Store from my iPad (3rd. generation - wi fi) in U$ 4.99. It does not work. I´ve tried to download the magazine several times and the only thing I read is "this page is not currently available". Also I have obtained my purchase receipt (sent by iTunes to my e mail), but when I click in the post a problem icon, it appears "page not found" in apples web page, so I can not post my claim. How can I obtain the reimburse of my money?? With that price I believe I can pay two susbcriptios to other magazines that will work and even buy more than three apps from the store.