The files can be donloaded as follows

my $file_size=-s "report_generator/".$file;
print $q->header(
    -type=>"text/csv",
    -attachment=> "report_generator/$file",
    -Content_Length=>"$file_size"
);
open (INFILE,"report_generator/".$file) or die("FAILED TO OPEN CSV FILE");
binmode(INFILE);
binmode(STDOUT);
while (){
    print $_;
}
close(INFILE);
unlink ($file);
exit;