Stenger & Stenger Law Firm Called my phone and hung up after 2 rings Grand Rapids Michigan

So, i googled the phone #, and called them back; told them I was returning their call.  They asked for the last 4 #s of my social security number to identify the case.  I declinced, as I hadn't received any official notification of a "case" against me.  This call came approx. 1 month after my bankruptcy, which included foreclosure, had been entirely discharged.  Since all my old debts had been resolved, and there are no new, outstanding debts, it appears they just look for vulnerable people to harrass/threaten in the hope of collecting fees for themselves.  It has been several months since that call and I havent' heard from them again, nor from anyone claiming that I was in arrears with any financial obligations; neither has my bankruptcy heard from anyone.  So, if there was a legitimate need for Stenger & Stenger to contact me, it should have come to light by now.