So what you're trying to do is store multiple values for a given key. If it were me, I'd use a hash of arrays. Like so:

push @{$hash{$key}}, $value
[download]

Then, to extract them, you'd do something like this:

foreach my $key (keys %hash) {
   print "$key =>\n"
   foreach my $thing (@{$hash{$key}})
      print "\t$thing\n";
   }
}
[download]