Keep everything you have, but try adding this at the beginning of your start function:
for (c = 0; c < 12; c++)
{
PresenzeMazzoBanco[c] = false;
}
It was a bit confusing to read your code because the Unity forums removed all of your " [ i ]" and turned them into italic font commands. You can prevent this in the future by using code tags , which will also make the code look nice like here in my post.