Minor issue: Undefined offset notice on post-purchase page

I’ve just gone through the checkout process and encountered the following PHP notice:

Notice: Undefined offset: 0 in /path/to/wordpress/wp-content/plugins/gift-cards-for-woocommerce/giftcards.php on line 253

I did not use any gift cards, and no gift cards have been sold inside the system, so no one has any balance.

Cheers,
Eric

https://www.ads-software.com/plugins/gift-cards-for-woocommerce/