Position doesn't matter. You're using a callback to decide your program flow, but you're only supposed to use it to set variables.

use strict;
use warnings;
use Getopt::Long;

@ARGV = qw( --user user --password pass --fetch  bob );
{
    my $user;
    my $password;
    my $fetch;

    GetOptions(
        'fetch'         => sub {
            my( $n, $k, $v ) = @_;
            print qq~
name  = $n
key   = $k
value = undef
~;
            $fetch = $k ;

        },
        'user=s'        => \$user,
        'password=s'    => \$password,
    ); 

    SOMETHING( $user, $password, $fetch );
    die "THE END";
}

sub SOMETHING {
    my( $user, $password, $fetch ) = @_;
    print qq~
    user = $user
password = $password
   fetch = $fetch

~;
}
__END__
$ perl f.pl

name  = fetch
key   = 1
value = undef

    user = user
password = pass
   fetch = 1

THE END at f.pl line 27.
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