Who I have the same questioned this topic

I have a Samsung Galaxy S6 that all of a sudden, the names in my contacts changed on their own to other contact numbers. Example: When Suzie calls me, the phone displays Paul's name but Suzie's telephone number.  Likewise in "recents" the phone shows Paul incoming call but he did not call me. Susie is the one who really called. Has anyone else experienced this before? Do I need to scrap the phone? Need help.