Check that you have not already redeemed the token to your account. You can do this by navigating to https://ccsk.cloudsecurityalliance.org/en/tokens to see what is listed there.
Check that your CCSK account is registered with the same email that you provided in order to receive your token code. If the email addresses are different, you will not be able to redeem your code. If you have created an account with the wrong email please create a new account with the correct email.
Check that you are redeeming your token on this page https://ccsk.cloudsecurityalliance.org/en/tokens/single/redeem. Enter your code there and press 'Claim Token.' Also ensure that there are no leading or trailing whitespaces when you copy your code into this box.