It is possible to unsubmit a level while the payment process is not complete. To unsubmit the level, you must delete the invoice opened when a level is submitted.
In the payment process
In the payment process, click on 'Cancel Invoice' to cancel the invoice.
If you are already in step 2, you need to click 'Back to invoice address' to cancel the invoice.
How to enter the payment process
On the dashboard, you can click on 'Continue Payment Process' to continue the payment process. Follow the steps above to proceed.