I didn't know quite where to start with this. Your convertCsvToHash() code clearly does not do what you are expecting. There are some modules that can do this rather well, but below is my hint in a straightforward way. Indentation is important and is great impediment to reading your code. I have never used the XML writer code but hopefully solving the CSV part will help you out.

Update: Note to the OP: You provided simple example data, but perhaps too simple. The kind of problems that can crop up in these CSV files are legion. "Fred Smith, MD", "George Bush, Jr" or "Widget, INC". Even parsing phone numbers can be a whole can of worms. Parsing a full blown CSV file is better done with a module because the details are a lot harder than one might think. However, you have another big problem, the XML. But now maybe you can focus on getting XML working and then come back to the CSV part when you discover that neither one of our simple approaches will work with complex data. BTW, kudos to you for providing code that actually compiles and runs albeit with the "wrong' result.

use strict;
use warnings;
use XML::Writer;
use IO::File;
use Data::Dumper;

my $CSVfile='1.csv';

my ($arrRef,@keys)= convertCsvToHash($CSVfile);
print Dumper $arrRef;
print Dumper \@keys;


sub convertCsvToHash
{
        my $file = shift;
        my @AoH;
        open(FILE, "$CSVfile") or die "$!";;
        my $header = <FILE>;
        chomp $header;
        my @keys = split ',',$header;
       
        while (my $data=<FILE>)
        {
            my %hash;
            chomp $data;
            my @values = split ',',$data;
            foreach my $key (@keys)
            {
               $hash{$key} = shift @values;
            }
            push @AoH, \%hash;
        }
        
        return \@AoH,@keys;
}
__END__
$VAR1 = [
          {
            'Phone' => '1111',
            'Name' => 'A',
            'Company' => 'X',
            'Email' => 'a.x@aol.com'
          },
          {
            'Email' => 'b.y@aol.com',
            'Company' => 'Y',
            'Name' => 'B',
            'Phone' => '0'
          },
          {
            'Email' => 'c.z@aol.com',
            'Phone' => '2222',
            'Name' => 'C',
            'Company' => 'Z'
          }
        ];
$VAR1 = [
          [
            'Name',
            'Company',
            'Email',
            'Phone'
          ]
        ];
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