ACH- How to delete a pending transaction from the Ready To Submit screen

Tenant was set up on auto pay ACH 1st of month for October payment. A few days later I notice tenant logged on to website and processed another ACH payment that was applied to November. I sent email saying she had set up the auto pay feature when she logged on to pay September so the October payment was processed 10/1 and that the payment she made when logging in was applied to Nov.  Yesterday I noticed one of her payments was rejected/returned- I assume it is the one from the 1st but not sure.  In the return process it is showing up on the Ready to Submit screen including the NSF fee.  How do I delete this? I am afraid an employee will submit the transaction.  Thanks