Ans:
No, that is not the case. The CVV number (Card Verification Value) is used to determine the card's validity and expiration date. If you input the right CVV number, you will be requested to enter an OTP sent by the bank to complete payment. An error notice will appear if the CVV entered is incorrect. Except for the CVV number, the sites can keep your card information.
When it comes to blocking the card, keep in mind that your card information is the key to your account. If you block a card, that road to your account is closed, and payments made with that card will be denied.