Hey there, @sanchita
Bo here from Shopify Support!
Thank you for reaching out regarding this. Cards cannot be removed from your Shopify account through the admin, they can only be replaced. This is to ensure that there is always a card available to charge when your invoice is due. Once you add a new card to your account this is the only card that will be charged. If you would like to have the card taken off your account completely I can look into getting this sent to our Account Integrity team to get this actioned. Could you please explain why it is that you require this card to be removed?
All the Best,
Bo