As ironass said, there are alot of variant of the S4...sometimes confusing eh? Not to mention being careful about what you flash.
I'm not sure the PlayStore is available in China, but don't quote me
Are you from China?
Also as ironass said, can you post a link to the method you attempted?
Just as an FYI only
, I did see this about your device....if
it is the device
Samsung Galaxy S4 Duos (GT-I9502) Released With Exynos 5 Octa: How To Update It To ZNUAMDG Android 4.2.2 Jelly Bean Official Firmware [Tutorial]