They called my cell phone, then called my job harassing my co-workers

Called looking for a family member, couldn't give any information regarding the reason for the call but wanted me to give family member's phone number.  I don't give out phone numbers to anyone.....especially when they get rude with me on the phone.

A man called my phone, ask for someone I have never heard of.  I explained this was not her number, he wanted a number for her and I told him I did not have one, I didn't know her, and that this has been my number for over 20 years!  He said, "Oh really?"  I had to hang up on him, it seemed like he was stalling to keep me on the phone.

Its a bill collector for student loans

they also called asking for a family members phone number