I had very similar problem with my ipad 2. If apple support or geniuses are watching, here is my complaint and new perception of apple Inc:
1- apple should not proceed with an upgrade before checking the OS of the ipad and making sure it is upgradeable. Itunes told me i can
install ios 9.0.2 and I had 4.3.x on my ipad 2. The upgrade did not complete and did not give my any progress status. it was really
created by children coders I guess.
2- My ipad was stuck in recovery mode. I could not turn it off or do anything.
3- I was able to get out of recovery mode after torture during xmas day. I am not going to say how because Apple will probably try to destroy
that process.
4- Advice, do not upgrade your ipad OS using itunes. swallow the bullet and keep using it as is.
5- Apple is worst than IBM in terms of its anal retentive proprietary software and exploitation of customers.
6- Last, Apple fix your bloody itunes and do not cause ios devices to go into a limbo state. I expect at least that you do nothing if you cant upgrade.
Mo more ios purchases from me and my household.