How could I stop the update without switching off Wifi?

[AC Question]

I accidentally pressed the software update on my galaxy S5 (not rooted) & then it started downloading 942 MB update & there's is no any pause or cancel option except by switching off the Wifi & when Wifi is turned on again its starts automatically.I restarted the phone & nothing changed except that i couldn't see the progress of the download anymore,I went to settings to the applications tab to the disable or force stop the software update app but all the choices were freezed meaning that i can't opt for any of these choices.Any solutions.