wc-easycredit-cancel-unpaid-orders.php

<?php
/*
 * Plugin Name: Prevent Cancel Unpaid easyCredit Ratenkauf Orders
 * Author: NETZKOLLEKTIV GmbH
 * Description: Prevents unpaid orders paid with easyCredit-Ratenkauf from being cancelled
*/

// wc-easycredit-cancel-unpaid-orders.php

function wc_easycredit_cancel_unpaid_orders( $return, $order ) {
	if ( 'ratenkaufbyeasycredit' === $order->get_payment_method()) {
		return false;
	}
	return $return;
}

add_filter( 'woocommerce_cancel_unpaid_order', 'wc_easycredit_cancel_unpaid_orders', 20, 2 );