If you've accepted a payment during the day and later realised that the payment type has been entered incorrectly, it is possible to change it without having to delete and re-accept the payment. This is only possible if you have not yet sealed your banking. To do this:
Navigate to File > Maintenance and Reports > Daily and select Daily Banking.
Locate your payment and double click to open the payment record
Next to Payment Type you will see the current payment type in a drop down menu. Simply select the drop down and change the payment type, then click Save.