We have just tested it and we don't see any problem. If you still have problem, please send a screenshot to DriveHQ customer support.
Here is the instruction again:
To cancel your service, please logon www.drivehq.com, click on your Username to go to "My Account" page, then click on Subscribe --> Current Subscription. You should see a list of subscriptions you have ordered. You can then click on a subscription and cancel it. Once a subscription is canceled, you should see a confirmation message. You can also refresh your account balance to verify that your max storage space has been updated.
If you have only ordered one subscription, then your account type will also change from Paid Account (paid group account) to a (Free Service) True Account.
If you don't see a list of subscriptions you ordered, then your account type is a free servie account. Free service account usually doesn't need to be deleted. You just need to delete all files and don't logon again. The account will be disabled and deleted later.
Also, please make sure you reduce your storage and bandwidth usage before cancelation; if you have a group account, please delete all sub accounts.