Q: I have absolutely everything turned off on iPhone 6  and it is still using data!!! I have restarted and deleted apps and nothing is working!

Have you gone to settings>cellular> and turned it off? You may also be able to download your carriers app in the App Store to see a detailed breakdown of your data usage. -AJ

You have marked this as solved, is it solved?

If you have cellular data turned off and also have the device in airplane mode, there is no way you can be using cellular data. As far as questions about what might be using or have used your data, go to Settings>Cellular, and that lists your apps and what apps are using data. Are you using iCloud for pictures or anything else? Otherwise, you need to contact your carrier and have this situation examined.

If you truly have cellular data turned off 24/7 it isn't using data. But if you turn it on periodically, even for a few minutes, it will use data.

How much data is your carrier telling you you are using?

How much data usage is your iPhone telling you you are using in  Settings->Cellular->Cellular Data Usage

If you go to Settings->Cellular, and scroll down to the App list which App is using the most Data?

Go to Settings, turn Cellular Data off (see picture)

If you are surfing the web you are using data, unless you are connected to Wifi.  Data is your internet access. If use the internet you sue Data.

As Phil said, it sounds like you are using data, but are you using cellular or wi-fi. I'm wondering if you are understanding exactly what you are doing and what that counts against. Understand we are just trying to diagnose this, and it sounded like you were not sure what data usage is after this last post.

Glad you got it figured out.