Angular.JS HTTP POST Data Not Sending

I am fairly new to Angular.JS development but have had experience in the past with using PHP, HTML and JS so I am currently building a web application with Angular.JS as the frontend and PHP Slim as the API backend. I have been successful in implementing token-based authentication with Angular.JS $http.post for one of my calls but cannot seem to get the desired result in another $http.post request, which does not require the token authentication.

REQUEST 1 - Angular.JS (WORKING):

  function ($scope, $http, $location) {
  console.log("REACHED");

  $scope.master = {};
  $scope.activePath = null;

  $scope.New_Customer = function(customer, AddNewForm) {
      console.log(customer);
      console.log("2: " + JSON.stringify(customer));

      console.log("SCOPE: " + customer.status);

      $http({
        method: "post",
        url: "v1/customers",
        headers: {
            'authorization': token,
            'Content-Type': 'application/x-www-form-urlencoded'
            },
        data: $.param({first_name: customer.first_name, last_name: customer.last_name, email: customer.email, mobile_number: customer.mobile_number, home_number: customer.home_number, address_line1: customer.address_line1, address_line2: customer.address_line2, city: customer.city, postalcode: customer.postalcode, 'status': customer.status})
        }).success(function(result){
          console.log(result);
          $scope.reset();
          $scope.activePath = $location.path('#/Customers');
        });

      $scope.reset = function() {
          $scope.customer = angular.copy($scope.master);
      };

      $scope.reset();
  };
}

PHP (WORKING)

$app->post('/customers', 'authenticate', function() use ($app) {
        // check for required params
        verifyRequiredParams(array('first_name'));

        $response = array();
        $first_name = $app->request->post('first_name');
        $last_name = $app->request->post('last_name');
        $email = $app->request->post('email');
        $mobile_number = $app->request->post('mobile_number');
        $home_number = $app->request->post('home_number');
        $address_line1 = $app->request->post('address_line1');
        $address_line2 = $app->request->post('address_line2');
        $city = $app->request->post('city');
        $postalcode = $app->request->post('postalcode');

        global $user_id;
        $db = new DbHandler();

        // creating new customer
        $customer_id = $db->createCustomer($user_id, $first_name, $last_name, $email, $mobile_number, $home_number, $address_line1, $address_line2, $city, $postalcode);

        if ($customer_id != NULL) {
            $response["error"] = false;
            $response["message"] = "Customer created successfully";
            $response["customer_id"] = $customer_id;
            echoRespnse(201, $response);
        } else {
            $response["error"] = true;
            $response["message"] = "Failed to create customer. Please try again";
            echoRespnse(200, $response);
        }            
    });

However, for my login script, the data does not appear to be reaching the PHP file where the $http.post request always returns 'null' in the console.

REQUEST 2 - Angular.JS (NOT WORKING)

  function ($scope, $http, $location) {
  console.log("REACHED");

  $scope.Login = function(customer, LoginForm) {
      console.log(customer);
      console.log("2: " + JSON.stringify(customer));

      console.log("SCOPE: " + customer.email);

  $http({
    url: "v1/login",
    method: "POST",
    headers: {'Content-Type': 'application/x-www-form-urlencoded'},
    data: $.param({email: customer.email, password: customer.password})
}).success(function(data, status, headers, config) {
    $scope.data = data;
    console.log($scope.data);
}).error(function(data, status, headers, config) {
    $scope.status = status;
    $scope.data = data;
    console.log($scope.status + " " + $scope.data);
});  
  };
}

PHP (NOT WORKING)

$app->post('/login', function() use ($app) {

        // check for required params
        verifyRequiredParams(array('email', 'password'));

        $response = array();
        $email = $app->request()->post('email');
        $password = $app->request()->post('password');

        $db = new DbHandler();
        // check for correct email and password
        if ($db->checkLogin($email, $password)) {
            // get the user by email
            $user = $db->getUserByEmail($email);

            if ($user != NULL) {
                $response["error"] = false;
                $response['name'] = $user['name'];
                $response['email'] = $user['email'];
                $response['apiKey'] = $user['api_key'];
                $response['createdAt'] = $user['created_at'];
            } else {
                // unknown error occurred
                $response['error'] = true;
                $response['message'] = "An error occurred. Please try again";
            }
        } else {
            // user credentials are wrong
            $response['error'] = true;
            $response['message'] = 'Login failed. Incorrect credentials';
        }

        echoRespnse(200, $response);
    });

Console log:

app.js:148 REACHED
app.js:148 REACHED
/contacts_app_2/#/Login:1 POST http://localhost/contacts_app_2/ 412 (Precondition Failed)
Navigated to http://localhost/contacts_app_2/
app.js:148 REACHED
app.js:148 REACHED
app.js:151 Object {email: "[email protected]", password: "testpassword123"}
app.js:152 2: {"email":"[email protected]","password":"testpassword123"}
app.js:154 SCOPE: [email protected]
app.js:167 0 null
Navigated to http://localhost/contacts_app_2/
app.js:148 REACHED
app.js:148 REACHED

I cannot seem to figure out why my first request (to create a new customer works) yet to login does not work. Any help with this would be greatly appreciated as I have spent time looking through the forums for other answers but have not yet found a way to resolve this issue.