Data plan being used even when its OFF

[profyler]

I have the weirdest problem on my device

My data plan is always set to be disable (off). I only use wifi, and never use data plan
Even so, i receive a message every day for my carrier saying they have discounted $ from my plan because i used data plan. I should receive this message only those days that i use the data plan conection.

How the **bleep** is an app or android or some system activating my data plan even if its set off ??

Can android or a third party app activate data plan? I guess not.

Does stamina change this somehow?

This immediately started the day i bought myself the Z1c. Didnt have this on my moto g or optimus hd.

i have no idea else.. i tried everything.

When i go to the screen that shows the apps that used data, its complete blank with 0,00Bytes used.

as i said, this didnt happen with my previous phones, so im pretty much sure that is something with the z1c.

any help is apreciated.

[_alexdon_]

There could be background data going on,look at the first apps and check that out.

[profyler]

what first apps? if there was background data, it would be showing on "data usage", but there nothing.

im lost.

[_alexdon_]

Don't you have a list of apps using data plan?

[cableguy4]

Are you receiving mms 's?

[profyler]

Not at all. no aps using it. It must be something that the sony device is making. didnt had this since one week ago, after i purchased the z1c, so its definetely something with this device.

Im making tests every single day to find out what could be causing this. (device is stock, no root nor unlocked BL):

- Next tests
remove all apns

- yet disabled:
4g - no effect
autoupdate sus - no effect
geotag the photos - no effect
sony account manager - no effect
sony taken as adm cell - no effect
removed the sony location service cell - no effect
config updater app - no effect 
re setting apn - no effect
off stamina + wifi spot - testing
APN defaul (no suppl) - testing
only data apn (no mms) - testing

 example: 

day 7: data was off but i was charged for using it

day 8(today): data was off but i was already charged for using it

[_alexdon_]

This is a strange issue.Have you considered repairing your software via sony update service?

[profyler]

i had the mms apn settings, but im not using it (didnt receive nor make a mms msg)

im testing today without the mms apn too.

[profyler]

@alexdon Thank you for your replies. But reinstalling the firmware will probably no solve this issue. anyway, since kitkat is on the verge of coming, i will update first to KK using SUS, and then make a hard reset, and see if the problem goes. But honestly, i dont think so, i really think that some Sony native software is bypassing the data plan OFF option.

[_alexdon_]

Have you tried booting in safe mode?See if the same occurs:

http://talk.sonymobile.com/t5/FAQ/How-to-boot-your-phone-into-safe-mode/m-p/348008#U348008