Contacts with same phone number

[red dawg]

I have multiple contacts with the same home phone numbers. One situation is is my sister and my brother-in-law. When I call my brother-in-law at home it dials his home number but the name shone on the caller ID is my sister's. I have the same problem when my wife calls me, the name on the screen is mine but the voice tells me my wifes name. It seems the voice command, caller ID and call log all may use different criteria.