In the spirit of TIMTOWTDI:

my $handles = {
  400 => 1,  # BAD_INPUT
  403 => 31, # SERVICE_ACCESS_ERROR
  500 => 32, # SERVICE_EXECUTION_ERROR
  503 => 30, # SERVICE_ERROR
};
for ($response_code) {
    if ($_ == 200) {         # OK
        print_response $response_content;
        exit 0;
    };
    if (defined $handles->{$_}) {
      exit $handles->{$_};
    }
}
[download]

$handles could also be a CODE refs that do something, then exit:

my $handles = {
  200 => sub { print_response $response_content;  0}, # OK!
  400 => sub { 1},                                    # BAD_INPUT
  403 => sub {31},                                    # SERVICE_ACCESS
+_ERROR
  500 => sub {32},                                    # SERVICE_EXECUT
+ION_ERROR
  503 => sub {30},                                    # SERVICE_ERROR
};
for ($response_code) {
    if (defined $handles->{$_}) { # check for 'CODE' ref up to you
      exit $handles->{$_}->();
    }
}
[download]