Recently I got a iPhone 5 with iOS 9.3 installed. On connecting it to my computer iTunes said that I needed at least iTunes 12.2.2. I had 12.0 at the time. Mac Running Yosemite.
I clicked download, and App Store launched, and said I had no updates available.
Went through this loop several times.
Spent an hour on the phone, while the very personable agent walked me through the direct link (support.apple.com/kb/dl1814) Clicking the download button there got me to another page. Clicking download there got me a "Thanks you for downloading..." but the download didn't begin.
I repeated this step with chrome, firefox and safari. No joy.
Booted into safe mode. Didn't help.
Went to two other computers, my wife's where I don't have a login, and my laptop, which runs snow leopard.r No joy from either of those.
We left the ticket unresolved.