And if you have one of these modules, then I too am sorry, because they are kinda obsolete - I noticed my local Jaycar selling them off slightly cheaper last week.
Nowadays, you use the stackable MAX7219 modules, quite cheap from eBay.
Four of them gives you a 16 by 16, but you can easily stack more.
You can then forget about multiplexing and uniform, bright illumination of the display. You use the "Parola" library which is now in the IDE to control them.