RapBatLe on "[Plugin: WooCommerce - excelling eCommerce] Price"

if ($this->price!=='') :
				if ($this->variation_has_sale_price) :
					$price .= '<del>'.woocommerce_price( $this->regular_price ).'</del> <ins>'.woocommerce_price( $this->sale_price ).'</ins>';
					$price = apply_filters('woocommerce_variation_sale_price_html', $price, $this);
				else :
					$price .= woocommerce_price( $this->price );
					$price = apply_filters('woocommerce_variation_price_html', $price, $this);
				endif;
			endif;

this code i extract from classes/class-wc-product-variation.php and you see this that tags <del></del> and <ins></ins> is present but doesn't work :( I comment complete this if and also no stress code work perfectly, so problem is in another thing