In QuickBooks Online, regardless if you use the account or not, the system will continue to charge you for the monthly subscription. You'll want to unsubscribe from your QBO account, so you'll no longer be charged. Here's how:
Click on the Gear icon.
Select Accounts and Settings.
Choose the Billing & Subscription tab.
In the QuickBooks section, click on Cancel.
Follow the steps on the screen to cancel your subscription.
Once these steps are complete, you'll get an email with a confirmation that you've cancel your subscription.
Also, you may consider reaching out to our Customer Care Support team. They have tools to pull up your account and, they can further assist you with account charges questions.