I can see you've encountered difficulties with our chat support, and we appreciate your patience, alistaircole. Let me address your concerns about canceling your duplicate QuickBooks Online (QBO) accounts.
The process for canceling QBO accounts depends on how you initially subscribed. If you signed up through a mobile app store, you must go to your app store to cancel it.
Here's how to cancel an account purchased online directly from Intuit:
Sign in to the duplicate account you wish to cancel as an admin user.
Navigate to Settings ⚙ and select Subscriptions and billing.
In the QuickBooks section, select Cancel Subscription or Cancel Online. If you're canceling a trial, choose Cancel trial.
Follow the on-screen instructions to complete the cancellation.