Default Downgrade of s4 gt i 9500

Hi all !
I have recently purchase samsung galaxy s4(i9500). Ithought thatit would be 4.2.2 jelly bean android os before purchasing.but i got 4.4.2 kitkat os.as a result of it my ram run 1.34-1.56 gb out of 1.82 gb. But one of my friend using it bellow 1gb ram in 4.2.2 jelly bean with same apps.i have also tried to download 4.2.2 for i9500. But no one links are not working.
Please send me a link where i can download the official firmwire of 4.2.2 and inform me the details procedure.
Thanks for advance.
You can mail me at arindampanda54@gmail.com

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