I want to edit a excel file without losing previous data

For that I try a code

#!usr/bin/perl


#use warnings;
#use strict;
use Spreadsheet::WriteExcel;
use Spreadsheet::ParseExcel;
use Spreadsheet::XLSX;
use Spreadsheet::Read;
use DBI;
#use POSIX qw(strftime);

my $dbh = DBI->connect("DBI:mysql:database=MIS_Reports;host=172.16.15.
+104;mysql_socket=/opt/lampstack-5.5.27-0/mysql/tmp/mysql.sock","root"
+,"",      {'RaiseError' => 1});

#Selecting the data to fetch
my $sth = $dbh->prepare("SELECT * from MIS_P2P");
$sth->execute() or die $DBI::errstr;

my $file_path= "/root/prac/packages/B_MUM_dashboard_month_latency_corr
+ected_FDB.XLS";
my $workbook = ReadData($file_path,cells => 0 );

if(defined $workbook->[0]{'error'})
{
    print "Error occurred while processing $file_path:".$workbook->[0]
+{'error'}."\n";
    exit(-1);
}

my $worksheet = $workbook->[1];
my $max_rows = $worksheet->{'maxrow'};
my $max_cols = $worksheet->{'maxcol'};


print "Rows    : $max_rows\n";
print "Colomns    : $max_cols\n";

while (my @row = $sth->fetchrow_array()) 
{
    my $excel_col=0;
    foreach my $value (@row)
    {
        $worksheet->write($max_rows+1,$excel_col,$value);
        $excel_col++;
    }

}
[download]

But I am getting an error

Error: Can't call method "write" on unblessed reference at excel_write.pl line 48.

I install that Spreadsheet::WriteExcel several times but still it showing error. I am not getting where I missed it