In CiviEvent, had a user that mistook chargeback for refund then using the Line Item Edit extension made more mistakes. The result is that for one event payee shows $500 refund more than correct. Upon looking at the transaction history I can see what happened but there is no user interaction to edit this area. Reading some other threads by Joe Murray states these are listed in two tables
civicrm_financial_trxn but it's not clear to me how to clear these entries.
He did say that any refunds or adjustments to registration activity should be done in CiviEvent and not CiviContribute. There should me a huge neon red banner that says that on the page or some restriction control on the contribution page with a notation to make any edits in the event. (See image)