Your account can get suspended either because your trial period has ended or if the payment was not successful while processing the renewal.
You would still be able to login and receive tickets, but the entire helpdesk would be on read-only mode, i.e. you would not be able to update/respond to tickets. If you are an Agent/Supervisor/Admin, you will see this error message: 'Limited access: Your account has been suspended. Contact your account administrator to reactivate'.
Account Administrators will see this error message: 'Limited access: Your account has been suspended. Click here to pay and reactivate'. Clicking on 'here' will take you (Account Administrator) to the Plans & Billings page inside your Freshdesk account.
Alternatively, you can email support@freshdesk.com so we can route you to the Billing team to get your account up and running.