You sorted by VALUES, instead of KEYS, then VALUES. Try:

foreach my $item (sort { scalar keys (%{$reg{$b}})<=>scalar keys (%{$r
+eg{$a}}) 
                                  ||
                                $b<=>$a   } keys %reg){               
+                     
    foreach my $case (sort {$a<=>$b || $reg{$item}{$a} <=> $reg{$item}
+{$b}} keys %{$reg{$item}}){
        print "$c = $item:$case\n";
        $c++;
    }
}
__OUTPUT__
1 = 282:37
2 = 282:38
3 = 282:39
4 = 212:41
5 = 212:42
6 = 212:49
[download]