Share your experience!
Jesus 7GB.
You haven't done the tossy Telstra Air crap have you?
Can you take a snapshot of your Data Usage Graph and try to capture the app thats at the top of the list?
If you don't know where to find it:
SETTINGS >> Wireless & networks - Data Usage >> Then click on the vertical ellipses >> Show-WiFi
Then do the same for WiFi
Then Go to the Phone dialer and dial:
*#*#4636#*#*
Then take a snapshot of Usage statistics, and sort by Usage Time
@alanmz5 wrote:
I installed an app killer and even now battery life is hit and miss.
I just read the rest of your post... I got to the word "Telstra" and I stopped reading and hit reply.
Get rid of the App Killer, it's a POS. There's only a handful that actually do anything - and for most of the effective ones, you'll need to Root anyway. You want to stop the app, not kill it.
Most of those pos apps that claim to save your battery do nothing other than close the app, which your system has set to restart on termination... so it just ends up starting and stopping and starting and stopping.
You can get a few apps that freeze. It's basically put the app in to its stop state: except for, you wont have the app readily available through the UI until you unfreeze it. With a stopped state, you can just activate the app yourself by opening it up again.
For example: If you were to try and kill the "Support App", You would still see the "Support" menu in the Settings menu... but I have it disabled.
Which - is also another way to freeze apps.
Here's where support is meant to be:
Are you tethering your connection to a laptop or pc?
edit: made the main question more noticeable in bold.
2ndedit: also, just want to point out that i wouldn't recommend rooting the phone, then just going killing apps or freezing them willy nilly without knowing which ones you can and cannot disable.
for example: in the last week in my attempt to get rid of facebook and reclaim internal storage space, so when I do a factory reset, it will never be installed, i managed to brick my z5c 3 times, put it in to a boot loop once, and also create an undeleteable object, which meant a reflash. but i did manage to get my system down to 7GB... huzzah.
@alanmz5 wrote:
Do you have a similar topic the Telstra site? I was going to post there to let everyone know I was working on getting a flashable image for the Compacts so everyone there could get off the Telstra branded stuff, and have it without any of the big apps to free up internal... I haven't had half the problems I've read there, and my phone was bought from the Telstra store a few hours after they received them last year, and they hadn't had a chance to set one up yet.
Telstra Air....never heard of it.....
so, no. 
Are you using your phone as a portable torrenting device like I am?
No mate, I don't have a topic on the Telstra site.
Here's the screen shots you asked for;
As you can see, the data usage has gone up by nearly 2 GB in 1 day.
I downloaded 2 apps, from GoPro, 1 was Capture [47Mb I think] and the other was Quik free video editor [~27Mb I think] anyway, no where near 2GB.
I use the phone as a hotspot for the laptop and tablet, always have done, never chewed so much data!!!
I hear what you're saying about the App Killer, although I don't fully understand it..... but I have to say, battery life has improved since I installed it. It is called Shut App.
I don't use it as a torrent device, wouldn't know how TBH.
I did buy a new lappy and had to download Windows Office Pro, but I'm sure that wasn't several GB. I have heard that Win 10 updates are data hungry but I haven't had that particularlappy connected for 5 days and still I'm chewing data.
Another odd thing when I did the upgrade was that my faverites on my phone were obliterated, and I mean completly. They were totally removed from my contacts. As I have a lot of business numbers in there, I'm not 100% sure how many I've lost but it *isses me off. I'm kinda wishing I had stayed with the Z3 compsct, it never gave me an once of trouble.
OK, I hope I have given you all the info you asked for. Sorry about the pic sizes, I'm sorta learning on the run here..... 
I need to wait until the pictures get moderated until i can see them... in the mean time....
here's a wall of text incoming about W10 and data
Mate, Thanks for your help, it's appriciated.