I find that hard to believe.
Do you have any working displays? If so then get it to display a simple message on the first row, crank up the contrast to maximum (darkest), and then disconnect the power to your Arduino.
Try not to disturb the wiring as you substitute one of the supposedly defective displays. Don't make any changes to the program even if the display geometry is different and reapply the power. You should see the same message.
Don