Surcharge not working

Hi,

I added below code to my site which should add a 0,05% surcharge to transactions in pound sterling:

/**
* Add a 1% surcharge to your cart / checkout based on delivery country
* Taxes, shipping costs and order subtotal are all included in the surcharge amount
*/
add_action( ‘woocommerce_cart_calculate_fees’,’woocommerce_custom_surcharge’ );
function woocommerce_custom_surcharge() {
global $woocommerce;

if ( is_admin()