Do not know who this is. Just got a call on my cell and I barely ever use that number for anything. Two places I have given my number recently: Experian, to receive a credit score for $1, and to some credit monitoring service I have a free one-year membership because some Citibank employee ran off wi a bunch of customers' credit info.
The only other thing I can think of is that an old college roommate lives in St. Louis and he's stalking me.