Upgrade to iOS 9 failure at "slide to upgrade"

Problem: Upgrade to iOS 9 freezes. Phone is now useless.

Hardware and Software: iPhone 4s with iOS 7 (latest) on upgrade to iOS 9. (I purposely chose not to upgrade to iOS 8, because everything I read suggested it would slow down the phone. And what I've read about iOS 9 made be believe it would be fast enough to work on this old phone.)

Update Process: done through iTunes (latest update) with wired connection between iPhone and iMac 20" early 2008 with OS X Mavericks (latest update.)

Specifics: The freeze occurs at the point that the phone shows the update is installed successfully, and that there are just a few more steps, including connecting to a wireless router. After having up to that point successfully swiped "slide to upgrade", at this point sliding no longer works.

I have searched the internet and found that many others are having this same problem. I am posting this as a new message to get the attention of Apple that this demands an immediate fix BECAUSE MY PHONE IS USELESS UNTIL IT GETS FIXED.

Perhaps this is isolate, and affects only a few customers. But, I'm a long term Apple customer, and I am beginning to lose faith in its moto that "it just works", because with this along with Apple Mail problems I have on a brand new MacBook Pro 13" early 2008 with latest OS X Yosemite, I am beginning to thing that for Apple, IT JUST DOES'T WORK -- reliably, anyway.

Seriously, please don't follow in the steps of Microsoft. Please focus on quality as an absolute. I want it to JUST WORK.

Please indicate if you too have this same issue so that we can escalate the problem for immediate attention and solution. MY iPHONE NO LONGER WORKS.