Default [Q] Problem with Samsung Flip Cover

Hello people, one question.

Recently I went to an Argentinian operator shop to buy a Samsung flip cover, for my galaxy s5 g900H variant. I replaced the back case for it, but, for my surprise, it didn't work. Sad, i went to another shop with the hope that it would work, but it didn't.

The s-view options doesn't appear on the accesories menu neither. And a man that was at the shop, said that I had to "scan" for the cover... is that true? or i had the bad luck that they gave me a disfunctional phone?

Also I saw that... when the phone is in stand by, the battery remains with the same percentage for hours, but when i start to use it, it drops 3-4% every 20 minutes.. is a hardware problem?

Thanks, Hernan.

PD: Sorry for my bad english, I am Argentinian.