I have a data plan for all of my smartphones, computers, and tablets, so I have to be very careful staying within my allotted usage. When I discovered that my iPad downloaded a 3 GB software update (not apps, the iOS update), I am not happy. I do not know how to turn off the automatic downloading of iOS updates. All of the answers I get on the Apple Support Communities tell me that iOS updates are not installed, only downloaded. It is the automatic downloading of iOS updates that is the problem, because my data gets unintentionally used. How do I turn off the automatic downloading of iOS updates?
You should also be able to go into General > Usage > Manage Storage and delete the iOS update from the device.
But it will just download again. You can't stop that easily.