Hey, thanks for the help. I've checked LocalBitcoin and Paxful however i can't trust the sellers since i had bad experience with seller who have good reputation and have their own website.
I also afraid trying purse.io since i see many recent bad feedback and their customer service is really bad when i had few question.
But, i found
http://steamgamesbtc.com which have good reputation and have running for long time, the rate is good as well
I see that it's a neat looking site, but is it really worth it for you? You're getting a 10$ giftcard from the site for 9,90$ worth of bitcoin. There is also the risk of Amazon freezing the giftcard, and you getting scammed.
I would not recommend buying from there, since it is not a known site. Steam giftcards for btc are useless now, since Steam now accepts bitcoin deposits. It seems like you have had bad experience on every site that sells amazon giftcards, so why don't you just use fiat for the purchases?