Basic Payment Method is part of Payment

The Basic Payment Method submodule no longer exists. The feature that allowed site builders to add a human-readable message (now with token support) to the payment form has been merged with \Drupal\payment\Plugin\payment\method\Base, which means that every method that extends this base class now has this feature. The basic payment method has been renamed to payment_basic, is now part of Payment itself and features the configurable final status message.

7.x-1.x

$controller = payment_method_controller_load('PaymentMethodBasicController);

8.x-2.x

$plugin = \Drupal::service('plugin.manager.payment.method')->createInstance('payment_basic');