How to update my iPhone 4 to iOS6?

I bought a new iPhone 4 8gb. It says mine has 5.1.1(9B206) installed, is there any way to get iOS6 or higher WITHOUT getting the new iOS7?!
I wish I had known it was going to have iOS5 installed because I pretty much HAVE to update to use most of the apps I want to use.
Is there any way of knowing before I buy the phone if it will have iOS6 installed on it? (Maybe by the box?) I'm thinking I can return the phone for one with iOS6 installed already.
I feel SCREWED!

It is no longer possible to upgrade to iOS 6 on devices that support iOS 7. Sorry!

Usually, you can tell what iOS version it might have on it just by looking at the box. If it has bubbles on it, it likely has iOS 4 or 5 pre-installed on it. If it has that iOS 6 version of those waves, it likely has iOS 6. If the icons have been completely redesigned, it likely has iOS 7 on it. This strategy only works if you are buying your iPhone in new condition.