use warnings;
use strict;

while (<DATA>) {
    my @cols  = unpack 'A8A11A9A9A*', $_;
    print join(',', @cols), "\n";
}

__DATA__
12345   DOE,JOHN   $50.00   REFUND   COMPLETE
12345   DOE,JOHN   $25.00   DENIED   COMPLETE
12345   DOE,JOHN   $75.00            COMPLETE
12345   DOE,JOHN   $10.00   REFUND   COMPLETE