Apple ID issues
Hello,
Before I got my new iPhone 8 plus, I was using someone's iPhone 5s because my phone was stolen. Now I have a new iPhone and I transferred all my data from the 5s to the new iPhone. I also signed out of the person's icloud account and created a new ID for my phone. The settings on my phone has all my details but the person's ID is still associated with my number. I have tried to remove this ID but I have not been successful. Whenever someone calls me or I call someone, the person's ID and name shows up instead of mine. Please how can I change this? I do have a different icloud account that is separate from this person's account.
Thanks for your help.
iPhone 8 Plus, iOS 12