Request $http does not return values

Question

I’m trying to set up a Factory for various requests, but the result is always undefined, what could be wrong?

My Angularjs:

(function(){
angular
.module("store", ['ui.bootstrap', "ngAnimate", "ngSanitize"])
.controller("homeCtrl", appController)
.factory('httpService', function($http, $q){

    return {
        getData: getDataHandler
    };

    function getDataHandler(url, data){
        $http({
            method: 'POST',
            url: url,
            data: {'p': data}
        }).then(handlerSuccess, handlerError);
    };

    function handlerSuccess(response){
        return response.data
    }

    function handlerError(response){
        if(!angular.isObject(response.data) || !response.data.message){
            return $q.reject('Ops! Aconteceu algo errado.');
        }
        return $q.reject(response.data.message);
    }
});


function appController($scope, $http, httpService){

    console.info(httpService.getData('php/list.php', null));

    $scope.page = httpService.getData('php/list.php', null); 

}
})();

My list of examples:

<?php
$p = json_decode(file_get_contents("php://input"))->p;

$list = '{
    "title": "Aulas",
    "categorias": [{ 
        "nome": "Matemática",
        "subcategorias": [
            "Algebra",
            "Estatística",
            "Cálculo I",
            "Cálculo II",
            "Cálculo III",
            "Geometria Analítica"
        ]
    },{ 
        "nome": "Engenharia",
        "subcategorias": [
            "Materiais",
            "Estrutural",
            "Elétrica",
            "Química"
        ]
    }]
}';

 print($list);