call thumbnail and excerpt

what’s my wrong?

.
.
.
if ($url) {
            $prefix .= '<a' . self::shortcode_attr('href', $url);
            unset($params['id'], $params['type'], $params['anchor']);

            foreach ($params AS $attr => $value) {
                $prefix .= self::shortcode_attr($attr, $value);
            }

            $prefix .= '>';
        } else {
            $prefix .= '<a href="#" class="missingLink">';
        }

        $content = do_shortcode($content);
        $suffix .=
		'<?php
			$post_id = $params['id'];
			$my_post = get_post($post_id);
			$title = $my_post->post_title;
			echo $title;
			echo $my_post->post_content;
		 ?>
		</a>';
        return $prefix . $content . $suffix;
    }

in rb-internal-links.php line 114
i add this line to call image :
$image = get_the_post_thumbnail( $post->ID, ‘thumbnail’ );
but it not work ??
cant help me ??
if you know please help me.
thanks.