There are two possible scenarios a user can encounter with this problem: first, the owner cannot delete a contact literally; second, the owner can successfully delete a contact but then it would come back on the Contacts list.
“Hi Droid Guy,
I have a little problem with my phone, I hope you could help me. Recently, it seems like I’m seeing duplicate contacts on my phone. I don’t know what happened or what I did but when I tried deleting one of them, I just can’t do it. The contact stays on my list and I just can’t make alterations.”
Network outage is affecting your area.
Inconsistent network connection.
Mobile data is turned off, or you are roaming and have your device set to not use data when roaming.
Currently connected to a poor Wi-Fi network.
Device software is not up to date.
Syncing online contacts is disabled.
Contact is resyncing to device from an account.
Step 1: Check service area. If this problem happens when you’re in a specific area, it could be that the service is poor or there is no service at all. For contacts that are abstracted from an online account, it is imperative to have an active internet connection or mobile data to manage it.
Step 2: Turn WiFi off, turn mobile data on. If your phone is connected to a WiFi access point, try disconnecting it and turn your mobile data on. This would make sure you have a good connection online so you can manage your contacts.
Step 3: Turn on sync. Turn on synchronization for one of your accounts. From the Home screen, tap the Menu key, choose Settings, the go to Accounts. If you have two or more accounts, touch the one you want to sync then touch Sync Contacts to mark the checkbox. Your device will begin syncing.
Step 4: Delete contact from account. Once syncing was turned on and still you wouldn’t be able to delete a contact, you might as well try to delete it from your Google or Samsung account. While Android can manage contacts synced with it, there are times when basic functions fail.
Step 5: Update software. I couldn’t emphasize enough the importance of having an update firmware, so if there is an available update ready to be pulled down and this problem happens, take time to update your phone because maybe it’s just what you need.
Tell us your phone problems
The solutions we provided here are based on reports and testimonies from owners who have encountered these problems. I also ask my XDA developer friends regarding some of the problems. Now if you have other problems or questions with your smartphone that you want answered, don’t hesitate to send us email at email@example.com.
We don’t guarantee a reply to all emails because we receive hundreds of them daily, but rest assured your email messages will be read by me. But I urge you to provide as much details as possible so I could easily find references and compare your problems with reports from other owners. If your problem is as common as others, there could already be solutions that exist and I would surely point you to them. Screenshots often help so attach one if you can.