Cash on Delivery for specific country (shipping address)

Hello, I’ve implemented cash on delivery for specific country with this code:

add_action( ‘woocommerce_after_single_product_summary’, ‘comments_template’, 50 );
function payment_gateway_disable_country( $available_gateways ) {
global $woocommerce;
if ( isset( $available_gateways[‘cod’] ) && $woocommerce->customer->get_country() <> ‘RO’ ) {
unset( $available_gateways[‘cod’] );
}
return $available_gateways;
}
add_filter( ‘woocommerce_available_payment_gateways’, ‘payment_gateway_disable_country’ );

In this case, “Cash on delivery” is available only for Romania. I want to make “Cash on delivery” available only for shipping addresses located in Romania. The problem is that when I select COD, I still have both billing address and a shipping address. The billing address is useless because the person will pay at the shipping address. And if I select as billing address a location from Romania and as shipping address a location from Germany for example, Cash on delivery will still be available even if the product is shipped to Germany. What can I do to remove the billing address if I select Cash on delivery and to make COD available only for specific countries from the SHIPPING ADDRESS not the billing address.

Thank you,
Andrei