I am an emergency answering service for doctors after hours. When a call is placed I set a timer on it and call my caller back to ensure that they’ve heard from a doctor. Here is an exchange with a nurse.
Me: Hello, I’m checking to see if you’ve spoken with the on call physician yet.
Nurse: How did you get my cell phone number? I didn’t give you my cell.
Me: Well. You gave me a number and I confirmed it with you on the previous call.
Nurse: Yes but this is my cell phone number. Not my work phone number!
Me: The caller ID is the office number so you had to have given it to me.
Nurse: I did not give you my cell!
Me: Okay, but what are the chances that I just guessed your cellphone number including the correct out of state area code?
Nurse: Yeah okay, I guess I gave you my cell.
YEAH, YOU DID.