Shared/same contact as my dad

So my dad and I went to Verizon to get a new phone and the had to swap are SIM cards. After they did that they said everything should be fine but when I got on my phone we had a shared contact. When I try to change my name in my phone it will also change his. So when I call him it looks like I’m calling my self vise versa. Does anyone know if it is an issue wi the version or apple. Ps Verizon said I need to contact apple support to get it fixed after they messed it up.