To
reverse the payment, go back to the original reservation and post the revenue
with a negative value and adding in the description that the charge is a
correction for the related invoice.
After
adding this charge, send it to the debtors account.
From
the Debtors account, reverse the payment by making a payment and putting in the description correction
for the related invoice and
save.
Correction
will appear on the past transaction tab.
After
correcting the invoice, go back to the original reservation to post the charges again. Send it to the debtors account. It will be in the current transactions tab as an unpaid invoice. Post the correct method of payment or correct amount of payment.