To resolve the issue of merging duplicated contacts while encountering the error “Oops something went wrong,” follow these steps carefully:

1. Check Account Settings: Make sure that the relevant accounts are configured properly on your device.

- Navigate to Settings > Mail > Accounts.
- Select each account and ensure that Contacts is enabled. This will help the system recognize and merge duplicate entries across all synchronized accounts.

2. Use the Contacts App: If you are on an iPhone or similar device, utilize the built-in Contacts app.

- Open the Contacts app.
- Scroll to My Card and tap View Duplicates.
- Review the suggested duplicates and select contacts to merge. Confirm any actions when prompted.

For detailed instructions, refer to Apple’s support page on this process - learn more.

3. Update iOS: Ensure that your device is running the latest version of its operating system, as compatibility issues can lead to errors.

- Go to Settings > General > Software Update.
- If an update is available, download and install it.

4. Third-Party Apps: Sometimes, third-party apps can facilitate merging of duplicates effectively. Applications like Cleaner Pro can assist in identifying and merging duplicate contacts smoothly.

- To use Cleaner Pro, download it from the App Store or an official source.
- Follow the app’s setup instructions to scan for duplicates and merge contacts.

5. Restart the Device: A simple restart can resolve temporary glitches.

- Hold down the power button until the shutdown slider appears.
- Slide to power off, wait a few seconds, and then turn the device back on.

6. Reattempt Merging: After following the previous steps, attempt to merge the contacts again.

If the error persists, it may indicate a more significant issue, such as account lock or a need for manual intervention. Consult the support community or explore additional troubleshooting threads like those found on Apple's forums for similar experiences - learn more.

Following these actionable steps should help you resolve the merging issue without further complications.