I got a new iPhone for Christmas and made my own Apple ID/iCloud so I could use it between my devices (I also have a Mac & an iPad) without sharing with my family. Today I realized that many of my parents' email & phone contacts have synced to my phone & iPad. When I try to deselect their groups on the contacts app, all of my contacts are removed. I have been using iCloud to backup pictures, etc., and it is all my own - no one else uses my Apple ID. I want get rid of the extra contacts without individually deleting them.
At some point somebody used your Apple ID on one of their devices (either OSX or iOS), or their Apple ID on one of your devices. Or, somebody might have connected your or their iPhone in your or their iTunes in the past.
And things got mixed up. If you don't have a local iTunes backup, there's not too much you can do to recover. And if you have a local backup chances are that it was made after the damage was done.
Having had the same mishap in the past, I have a couple 1000's pictures of my wife's iPhone mixed up with my personal collection.
If this is not enough, chances are (albeit small) that one of those devices is still connected to your Apple ID and syncing is still going on.
My following suggestion might seem stupid and short sighted, but if I were you, I would
- change my Apple ID password
- Delete all contacts on your device(s)
- Add all your contacts again from the beginning
I understand that, if there's a lot of data involved, adding your contacts piece by piece can be quite time consuming, but the effort might be worth it.
If you have access to a Mac, things can be facilitated quite a bit:
- You can use the native Contacts app to export your current data to csv, import it in Excel and manipulate chunks of data much quicker.
- Busy Contacts can do some of this for you, and it also can sync with other online addressbook services. If you have your contacts in e.g. gmail this can fasten the process.