Last month I noticed that I used 200MB after two weeks. I thought - ok, I used some internet so it could happen. But this month situation was the same and I rarely used internet. My internet data ended around May, 18. I checked Data Usage in Settings and it showed me that to the date of this post I used 419 mb (last month it was 276 MB) and the month is not over yet. 373 MB was used by Android OS, Firefox 12 MB, Email 8 MB and some other apps used around 1-4 MB. Yesterday I installed My Data Manager app by Mobidia to see precisely what app consumed my data. From 8 AM to 1 PM the phone used 18 MB. 73,3 % was used by something called Manager (with Android icon) and 20,5% was used by OS Services.
My Google Play apps updates only via wi-fi. My phone is always conected to my wi-fi from 6 PM to 8 AM, and almost all the time on Saturday and Sunday. I also noticed that when my phone is fully charged and connected to wi-fi, it lasts 2-3 days of normal using without charging, My record was 5 days. But when I'm disconnected from wi-fi, the phone asks for a charger after a 5-6 hours and the back of the phone is warm, sometimes hot. My signal strengh has all bars and my network type is HSDPA+.
Can anyone tell me what is causing this data used and my general problems, and how to solve it? My habits has not change, my aps has not changed, but the internet data usage and battery drain increased dramatically.
P.S. Factory Reset or changing the soft is a last restort.