Originally Posted by Planterz
That's certainly weird. Where are you viewing this data usage? Just the basic "Data usage" list in Settings? Scrolling through mine, I can't find "Play Services", just "Google Play Store" and "Google Services" (the latter being very minimal). If you used Google Play Music to stream audio, or whatever the TV/Movie app is called, it should show up as those, and not Google Play Store or Services or whatever.
I first noticed that behaviour yesterday when my carrier sent me a message, that the traffic included in my data plan was fully used. I then disabled the background data option for play services.
I look in the "data usage" statistic in the settings (Not sure if it is called like that, my android is in german). There is the entry "Google Play Services", but you are right, there is a seperate one for the play Store.
According to the entry, "Google Play Services" is the group with the following apps:
"Google Service ... "
"Google Backup ..."
"Google Play Service"
"Google Contacs ..."
Unfortunately, the full names are not shown, but overlapped by the statistic bar.
But thanks to checking that group I just got an idea, why this possibly could happen. I used Apps Ops recently to deny the access to some parts for play services, maybe it just tries to sync some settings, fails and try again every minute or so. I will try, if reverting those settings will solve the problem and will post the results.