Hi, @jackiehamnett.
 
To cancel your QuickBooks Online (QBO) account, you can follow the steps below:
 - Sign in to QuickBooks Online as an admin user. 
- Go to Gear icon and select Account and Settings.
- Select the Billing & Subscription tab.
- In the QuickBooks section, select Cancel.
- Follow the steps on the screen to cancel your subscription.
Once you're done, we'll send the account administrator an email that confirms we cancelled your subscription.
 
If the cancellation failed, I recommend contacting our QuickBooks Online Support Team have additional tools to pull up your account in a secure environment and cancel  your account. 
 
Here's how to contact our customer support:
 - Sign in to your QuickBooks Online company.
- Select Help (?) at the top right.
- Click Contact Us to connect with a live support agent.
I'll be around to help if you have any other questions, Have a good day ahead!