Server error after updating plugin

Following update to version 1.5.9 I got this error when server tried to create new refund:

Uncaught Error: Call to undefined method Automattic\WooCommerce\Admin\Overrides\OrderRefund::get_customer_id() in /var/www/hahishook.com/wp-content/plugins/woo-wallet/includes/class-woo-wallet-cashback.php:76 Stack trace: #0 /var/www/hahishook.com/wp-content/plugins/woo-wallet/includes/class-woo-wallet-ajax.php(193): Woo_Wallet_Cashback::calculate_cashback() #1 /var/www/hahishook.com/wp-includes/class-wp-hook.php(324): Woo_Wallet_Ajax->recalculate_order_cashback_after_calculate_totals() #2 /var/www/hahishook.com/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters() #3 /var/www/hahishook.com/wp-includes/plugin.php(517): WP_Hook->do_action() #4 /var/www/hahishook.com/wp-content/plugins/woocommerce/includes/abstracts/abstract-wc-order.php(1967): do_action() #5 /var/www/hahishook.com/wp-content/plugins/woocommerce/includes/wc-order-functions.php(626): WC_Abstract_Order->calculate_totals() #6 /var/www/hahishook.com/wp-includes/hahishook/admin.php(2366): wc_create_refund() #7 /var/www/hahishook.com/wp-includes/class-wp-hook.php(324): close_with_missing_handler() #8 /var/www/hahishook.com/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters() #9 /var/www/hahishook.com/wp-includes/plugin.php(517): WP_Hook->do_action() #10 /var/www/hahishook.com/wp-admin/admin-ajax.php(192): do_action() #11 {main} thrown