There have also been reports of the latest Windows update getting into an endless download/fail/download loop for some Windows 10 users.
Also it is important to note that Windows will revert to the default values of many settings that had be chosen previously.
Windows 10 is not a good choice of OS for anyone on a data capped service.
Also it is important to note that Windows will revert to the default values of many settings that had be chosen previously. - Gwalk
You really can not turn off auto update in Win10
IF you are connected wirelessly you can set your connection under Win10's WiFi settings to "metered" but that will only delay the update.
When you do finally update Win10 it will have likely reset all your previous custom settings including undoing the "set to metered" setting.
In addition to updates, wind10 will collect data from your computer and "share it" with MS. It is known as "Telemetry".
You are mistaken in thinking you have turned off Win10 updates.