[php]
/* Adding text before order information from "Thank you. Your order has been received." BEGIN */
add_filter('woocommerce_thankyou_order_received_text', 'woo_change_order_received_text', 10, 2 );
function woo_change_order_received_text( $str, $order ) {
    $new_str = 'We will contact you with a full quote for all the products you ordered and all shipping and/or import fees with instructions on the next steps.

';
    return $new_str;
}
/* Adding text before order information from "Thank you. Your order has been received." END */
[/php]