iPhone 6(S)/Plus Data usage gone wild??

[aslowdodge]

I have an Iphone 6s which I normally just use for calls. Maybe I ask siri for directions once or twice a month for and maybe check email once a month at best. My usage is always under 1gb by a longshot and my bill is $14 a month with xfinity. The last 2 months have been $54 and $84

Just yesterday I saw that the map app was running displaying my location. I swiped it to turn it off. When I got home The map app was showing my location again.

Is there a way to see which apps are currently running?
Is there a way to make sure no apps are running at all unless I launch them?
Finally is there an app that tracks data usage not on wifi?
Thanks

 

[noobinator]

Do you actually use the maps app? If not turn off location services for that app.