iTunes/App Store automatic updates are disabled in Settings but my iPad and iPhone STILL downloaded them.

The settings you are speaking of do not affect the iOS update. The iOS update can be auto-pushed to your device if/when:

The device is connected to external power/USB port on the computer

The device is connected to a working Wi-Fi network

The device has enough free storage space to accommodate the iOS update download

You can delete the downloaded update under Settings/General/Usage/Storage/Manage Storage, find it in the list (iOS Update), tap on the app, then tap the "Delete App" button.

The best way to prevent the auto-pushed update is to:

In your router's settings, set up a block (using Access Restrictions or similar in the router's web interface) to mesu.apple.com. This will prevent the devices from "phoning home" to Apple, checking for the update and getting the download pushed to it again (if no block is set up, it WILL get pushed again to the device, even if you remove it as above).

In the future to check for updates on the device, simply disable the Access Restriction block created above. After you've checked for updates, remember to reenable the Access Restriction block that you disabled.

Also beware the the block will only be in effect on the Wi-Fi network that you applied the block to. If you connect other Wi-Fi networks, you are again subjected to the auto-pushed iOS update.

Please tell Apple about your experience with the auto-pushed update at the link below. They are wrongfully using your data to download something that you may not necessarily want. I've complained numerous times myself. If I want to download the update, I'll do it as I see fit...and when I see fit.

http://www.apple.com/feedback/