Bitdefender Billed to new card when account number wasn't given to company.

I used Bitfinder anti-virus program for one year.  From July 2018 to July 2019.  On July 23 2019 I was issued a new account o my credit card.  I did not give the new account numbers to Bitfinder.  I was informed on Sep 9 that I was automatically billed for another year subscription.

 I emailed them back and asked them how did they bill me when I did not give them my new numbers.  They replied they used the same card on my initial order from July 2018.  I again told them that my card just changed in July, how did you get the new numbers in order to bill my new card?

 They never answered how, but did give me the refund.  I have the entire email chain in pdf form.