To cancel your subscription. From the Navigation Panel go to Settings.

You will see a "Modify Subscription" button below the subscription plans details in Settings> Company Billing> Modify Subscription

Click on Modify subscription

Upon clicking Cancel, you will see the following confirmation popup:

Once you click on Confirm Cancellation, You will see this message:

Whenever you try to access the canceled account you will see this message until you reactivate:

You can reactivate your sub-account by clicking the reactivate button if you cancel your subscriptions. Also, you will have the option to change payment methods if required. 

You can also reach out using the agency's email under company settings if you ever get locked out erroneously.