Reliable free VPN?

Hey there, I am pretty new to this, since I never actually needed the VPN. I want to buy hearthstone bundle from US. I know the trick with just rewriting the url, but this new bundle with for Hallow's end is not available on page, only ingame.

So what I am asking is, if you know some FREE VPN that will connect me to some US server, allows me to buy one thing from there and doesn't steal my bank acc info. Thank you for any help and suggestions