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If the same contact appears more than once in your phone's address book, you can merge identical contacts so that they will appear only once.
1. Find "Contacts"
2. Merge identical contacts
Press the menu icon.
Press Organise contacts.
Press Merge duplicate contacts.
Press the fields next to the required contacts.
3. Return to the home screen
Slide your finger upwards starting from the bottom of the screen to return to the home screen.