Retrieve AngularJS $http.post server data using PHP

I am calling a $http.post function but can not grab the data on the other side, the calls goes through successfully but can not retrieve the data in my PHP script

AngularJS:

    var data = {
        firstname: $scope.first_name,
        lastname: $scope.last_name,
        email : 'test@fff.com',
        user : userID
    };
    var config = {
        headers : {
            'Content-Type': 'application/x-www-form-urlencoded;charset=utf-8;'
        }
    } 
$http.post('http://xxx-env.us-east-1.elasticbeanstalk.com/apipost/updateusersetting/user/'+userID, data, config).success(function (data, status, headers, config) {
        alert('yay'); // this works and gets called
    })
    .error(function (data, status, header, config) {

});

Server side PHP:

    $data = json_decode(file_get_contents("php://input"));
    $email = $data->email;
    $user = $data->user;
    $firstname = $data->firstname;
    $lastname = $data->lastname;

Also tried this, doesnt work either

        $email = $_POST['email'];
        $user = $_POST['user'];//$data->user;
        $firstname = $_POST['firstname']; //$data->firstname;
        $lastname = $_POST['lastname']; ;//$data->lastname;