Unhappy [Q] Excessive data drain by the People Hub

Hello, I don't know where to ask this, asked on few places but didn't got answer.
Here is my problem: I'm using Lumia 520 with WP 8.1 Developer Preview. I'm experiencing huge amount of data usage by People app (hub). I have Outlook, Nokia and Google accounts added. Outlook set to download new content as arrive and Google account set to manually get new content. I get few mails every day on Outlook and not even check Gmail, but it keeps using my data, last two weeks it used 70 Mb for 2 days, then next week 68 in two days. Nothing changed for few days, I didn't changed settings for that app, and sudenly 2 days ago it spent 43MB of that when phone was idle, just for People app. Today, it is 84MB for People app, I've set data limit and turned off background data for all apps, even then it managed to spend few MB. I'm on limited data plan, and this is frustrating for me, it spends more than half of my data useless. When I connect phone to wifi, nothing happens, it spent 1MB on wifi on people app.. Help me, what to do to stop this?
Thanks!