I'm not sure who this is but the only calls I get like this come from Portfolio Recovery.  They call 3 or 4 times a day.  I just put them on my black list.  I asked them not to call me and I don't answer calls from numbers I don't know.  They always call on my cell phone and I'm not using minutes for anything other than my business.

I am in the process of sending them a cease and desist letter notifying them that this debt is beyond the statute of limitations, that I am disabled and can't work.  In Minnesota, the statute of limitations is 6 years.