I am not sure where you got the impression, but service ordering and canceling are both self-service. You can easily order our subscription(s) online. Canceling a subscription is much easier than ordering (as you don't need to provide your credit card info).
To cancel a subscription, you just need to log on to DriveHQ.com website, go to My Account page, click Manage Subscriptions. You will see a list of Order Item IDs. Click on an order item ID to cancel it.
If you have a Group (Enterprise) Account, please make sure to log on as the Group Owner. You will need to delete your sub-users and files before canceling your subscription(s). If you have any technical issues, please send an email to DriveHQ customer support.