Is there a way to Adjust a RECEIPT which is already CLOSED in a Past Period?

User found out that Cashier received a Customer Payment errounously acouple months ago..

Background:

2 months ago (previous period) Instead of an actual payment of $ 100, Cashier received it as $ 120.00. At that time, Accounting Applied the over payment of $20.00 to another Invoice (with Balance due) of the same Customer. That is, Customer had NO Unapplied or On Account monies. Then Period was Closed.

Issue:

Currently Finance is going thru Reconciliations and found out that Payment was incorrectly Received by the cashier. Finance would like this discripency to be Corrected. (other than issuing a Credit Memo to the Customer)

Although this Payment was received in a Previous Period which is now Closed in AR and GL modules, is there an option to Adjust the Receipt from the front-end?