Why my account is block?

Did you update the credit card information and associate it to your plan?

Check if you have a button to make a payment 

Make a payment now: Once your default payment method is all set and up-to-date for this plan, look for the Make my month l'y payment button in your account. This will trigger a payment attempt, and your service will be reactivated once the payment is confirmed.

Once your payment has been received and confirmed by Fizz (please allow a delay of up to two hours), your plan will be reactivated.

Source: https://fizz.ca/en/faq/how-do-i-fix-payment-issue