After getting about 10 calls a day, some back to back, I finally answered.  It was Convergent trying to collect an "outstanding" debt for Midland Credit Management.  I told the lady I had no recollection of a $7000 debt owed to Walmart.  She said it was "significantly lower", but due to interest it was now much higher.  I asked her to verify the debt by sending me information on the charges.  I hope she does.  I have no clue about this debt.  I did have an issue with identity theft a few years ago.