If a transaction has been entered in error, depending on the type of correction you need to make, you can do so.
Re-assign a transaction
Find the transaction on the constituents timeline and open it.
In the Transaction manage menu, click Reassign.
Remove a transaction
Find the transaction on the constituents timeline and open it.
In the Transaction manage menu, click Delete.
Enter a refund transaction
Create a payment method of refund.
Enter a new transaction with a negative amount.