Liberty (Collections) - Harassment

This past Friday I received two voicemails - one at work and one on my cell phone. My boss also received one on his voicemail. They were from a man named Eli Jones who said he was calling because his "client was preparing to serve me papers at work" and he "wanted to give me a chance to talk with his client to make arrangements to avoid this" (he told my boss he was trying to get in touch with me in an effort to do this since police would serve me at work). He called from a blocked number. Never told me who he worked for, or who his client was. He gave me a case number, and told me to call by Monday at 1pm to insure I would avoid being served. He left an 866 number. When I called the number back, they only answer "Liberty". When I Google the #, I am taken to a rental agency in Alabama (see below)

I am 99% sure this is some sort of scam, or a collection agency trying to get information from me or about me. I did have some financial issues about a year ago, which I have finally gotten some control of.

But isn't this kind of harassment illegal? Should I do anything? Anyone else have experiences like this, or with "Liberty"?

The phone # they left is 866-231-8453, which takes you here: http://www.hometownrentals.info/index-mobile.htm Do you think this is a front for a sleazy collector? I don't get why someone would leave a voicemail like that - yet alone 3 of them - and then have me call a rental agency; all voicemails left the same # and case #.