I've had my Desire S since May and my data usage is usually around 300mb per month. Last month I managed to max out my 500mb data usage in just 9 days!!! (I have received a text from Vodafone). 
Vodafone has no access to which websites and how for long per page I've been on. I even went into Carphone Warehouse & Vodafone stores and all they did was to stop the apps from running or killing apps. I've also been told to reset it to factory setting or get it fixed (even though they don't know why).
As the guy from Vodafone said, my phone has its own life doing it's own thing without my permission. Maps are constantly running & I have no idea why,
I'm connected to WiFi all evenings & weekends when I'm at home.
I have switched off auto sync, background data & GPS
I don't stream any videos or radios
I don't download any movies or music
I don't do any updates for my apps using mobile internet as it's slower & uses up my data.
I specifically use the internet for whatsapp, social networking websites, email, weather & news whilst I'm at work for distraction
My friends that go on youtube, listen to live radio everyday for nearly an hour, send/receive emails & download music don't even use that much data in a month.
I have downloaded ATK and Spareparts but not sure if they are useful. I've had mixed reviews about ATK, some says it's useful to kill tasks and some don't.
Yesterday I ran a test and left my mobile internet on for about 45 mins whilst I was at work and it has managed to use up about 20mb when I didn't even touch my phone.
Please help
SK

Vodafone has no access to which websites and how for long per page I've been on. I even went into Carphone Warehouse & Vodafone stores and all they did was to stop the apps from running or killing apps. I've also been told to reset it to factory setting or get it fixed (even though they don't know why).
As the guy from Vodafone said, my phone has its own life doing it's own thing without my permission. Maps are constantly running & I have no idea why,
I'm connected to WiFi all evenings & weekends when I'm at home.
I have switched off auto sync, background data & GPS
I don't stream any videos or radios
I don't download any movies or music
I don't do any updates for my apps using mobile internet as it's slower & uses up my data.
I specifically use the internet for whatsapp, social networking websites, email, weather & news whilst I'm at work for distraction

My friends that go on youtube, listen to live radio everyday for nearly an hour, send/receive emails & download music don't even use that much data in a month.
I have downloaded ATK and Spareparts but not sure if they are useful. I've had mixed reviews about ATK, some says it's useful to kill tasks and some don't.
Yesterday I ran a test and left my mobile internet on for about 45 mins whilst I was at work and it has managed to use up about 20mb when I didn't even touch my phone.

Please help
SK