Stimulus check deposited to an unknown account.

I checked the IRS site for the status of my stimulus check and it gave me the last four numbers to a bank account I don't recognize.  It said it was scheduled for deposit on 5/20.  It is now 6/8 and I have been trying to find out what to do next.  Calling the IRS 800 is difficult, I only get recordings.  Any help out there?