Stripe Billing in Laravel 5.1 Class not found

I'm trying to migrate the my app from Laravel 4.2 to Laravel 5.1. I've a stripe implementation here.

I've a BillingInterface.php and StripeBilling.php in my folder app\Acme\Billing.

I've the BillingServiceProvicer.php in app\Providers

In my PaymentController, I'm trying the following code and I'm getting an error:

$card = App::make('App\Acme\Billing\BillingInterface');
try {

   $new_card = $card->addcard([
   'customer_id' => $cards->customer_id,
    'token' => Input::get('stripe_token')
 ]);

Error:

ReflectionException in Container.php line 736: Class App\Acme\Billing\BillingInterface does not exist 

How can I solve this problem? update: @JeffreyWay Got some time?