I'll make sure that you'll be able to continue using your QuickBooks account, Chefdebi18.
You can settle your outstanding balance by updating your credit card details on the Billing & Subscription page. Here's how:
Log in to your QuickBooks Online company.
Click the Gear icon at the top.
Under Your Company, choose Account and Settings.
Select the Billing & Subscription tab, then click Resubscribe.
Enter the updated billing information, then follow the on-screen instructions.
However, If you're unable to update your payment details, I'd recommend contacting our Customer Care Team. This way, we'll be able to pull up your account and reactivate it for you.