I recently gave my old iPhone to my nephew, he switched it to his phone account, but somehow I now have his contacts on my new iPhone 5. When I look at my iCloud account, it lists his contacts. Is there any way for me to get my contacts back?

Question

I recently gave my old iPhone to my nephew, I did not clear out my old phone before I gave it to him, when he transferred to his account, he had my iCloud info on the phone, and it updated the contacts on my new iPhone 5 to his contacts. Is there any way for me to get my contacts back?

Answer 1

This is caused by using the same iCloud account on both phones.  When you do this any data you sync with the shared iCloud account such as contacts is merged and will appear on all devices connected to the account.  To fix this you both need to have separate iCloud accounts (you can continue to share the same Apple ID for purchasing from the iTunes and app stores). 
Decide which iPhone will be keeping the current iCloud account.  On the one that will be changing accounts, if you have any photos in photo stream that are not in your camera roll or backed up somewhere else save these to your camera roll by opening the photo stream album in the thumbnail view, tapping Edit, then tap all the photos you want to save, tap Share and tap Save to Camera Roll. 
Once this is done, go to Settings>iCloud, scroll to the bottom and tap Delete Account.  (This will only delete the account from this phone, not from iCloud.  The phone that will be keeping the account will not be effected by this.)  When prompted about what to do with the iCloud data, be sure to select Keep On My iPhone.  Next, set up a new iCloud account using a different Apple ID (if you don't have one, tap Get a Free Apple ID at the bottom).  Then turn iCloud data syncing for contacts, etc. back to On, and when prompted about merging with iCloud, choose Merge.  This will upload the data to the new account.
Finally, to un-merge the data you will then have to go to icloud.com on your computer and sign into each iCloud account separately and manually delete the data you don't want (i.e., deleting your nephew's data from your account, and vice versa).
As for recovering your lost contacts, if they aren't on icloud.com when you check from your computer, you will have to recover them from a backup source.  You could try restoring to your last backup but this doesn't always work for contacts.  (Chances are you nephew deleted your contacts from his phone, not realizing it would also delete them from yours.)