Who called from 5030000000

My caller ID shows this number about once a month.  No message is left on my answering machine...

Ms Lopez from Professional Credit Services, a collection agency. This is a personal message for ______. If this is not _____ please hang up now. This is a collection call regarding a debt, please call us back at 541-749-9689 or 1-800-821-3637

this number is been trying to call me everytime I'm going to take a nap.
I want this people to stop calling me.

i get a call every other day at least.  they have called my phone past 11pm before and woken me up.  no message is ever left and i do not plan on answering.  it is getting quite annoying.

1-503-000-0000