<?php

// Complete order if it was a credit card order or other instant payment type
add_action( 'woocommerce_payment_complete', function ( $order_id ) {
  $order = new WC_Order( $order_id );
  //$payment_type = $order->get_payment_method_title();

  // No updated status for orders delivered with Bank wire, Cash on delivery and Cheque payment methods.
  if ( in_array( $order->get_payment_method(), array( 'bacs', 'cod', 'cheque', '' ) ) ) {
    // Credit: https://stackoverflow.com/a/35689563
    return;
  }
  
  $order->update_status( 'completed' );
});