Has anyone received a postal notice for a package or been contact from Colorado

There's something strange afoot I got this notice in the mail stating I have a package and to call this number 800-683-9758 they give you a reference number and when you put it in its says this prob has been resolved. Then it's says press o for assistance then a minute later it's says goodbye. I thought this was very strange so I put the number in a search engine and all these people are going what the fuck is this. I also found one sight that said it was a phone detective or some kind of tracing system does anyone know what this is or have you received a letter or phone call my friends and relatives have already been contacted