Delete read only contact

I screwed trying to add a contact after they called me. I clicked on the little i but I didn’t save it right. Somehow his name, Bill, got linked to someone else, Bob. When I click on Bill, Bob’s info comes up with his name and phone and email were all correct . No mention of Bill. I’ve tried to delete Bill and it says it’s read-only and won’t delete. If I follow your instructions and turn off contacts, will it delete all my contacts?