IOS 10-Whatsapp background activity is draining my battery. How to stop it?

I have the entire background app refresh turned off but some apps still show background activity. That seems to be the way iOS works. Some apps don't care about background app refresh setting. I'm running iOS 9 btw.

Settings>General>Background App Refresh>Whatsapp>Off.

I've done this and yet on battery settings it still shows whatsapp background activity with a huge %

If turning off background refresh didn't work your only other option is delete the app.

Same problem here, turned everything off and still have many apps draining battery with background refresh