my @monthname = qw(January yadda yadda December);

open FH, '<', 'data.csv' or die "can't open data file: $!";

while (<FH>) {
   chomp;
   my ($last,$first,$title,$month,$amount) = split ',', $_;

   my $result = $template->fill_in(HASH => {
      name   => "$title $first $last",
      month  => $monthname[$month],
      amount => sprintf('%.2f',$amount),
   });

   die $Text::Template::ERROR unless $result;
   print $result;
}