Increase voltage from 5 to 12V to deactivate a display
So what you need is a level shifter. PD1 through PD7 need to swing from low (0 volts) to hi (+12V)

One way might be to use an inverting transistor (PD1 out to 10K resistor to base, emitter to GND, collector to R11) AND in the code, to invert all your logic outputs, that is assuming you can reprogram it.

If you can't fix the code, then you need 2 inverters.

Another method might be to add a 5V zener in series between the microcontroller output and the current limiting resistors (R5 thru R11) so that when the output goes hi, there is only 2 volts to drive the led. Or even simpler add Just one zener in series with your 12V supply before the BC558 transistors. Your display might be a little dimmer, but will cut off more effectively. You can bring the brightness back up by lowering the value of R5 thru R11.