Late 50's Movie Involving a Supermarket...

[thenetwork]

This one just jumped into my mind...Twas one of those old weekday afternoon movies that was used to fill a 2-hour spot on the schedule:

It was a Black & White movie from the latter half of the 50s.  The movie centered around a supermarket, whose outdoor sign was a spinning neon Dutch windmill. 

At one point in the movie, one of the main characters was driving a T-Bird, with the speedometer clocking in at over 80 MPH.

The movie ends with one of the characters calling the supermarket from a pay phone, then leaving the phone off the hook in order to prevent the store to call out.  He then goes into the supermarket to rob it, and instead he kills the manager.

Any clues as to what this B-movie was???