Is it possible to update, in the Billing module, an incorrect DEPT value derived from an AP voucher?

Hello,

We are on PS 9.2 PUM 47 and have the following situation with a rate-based customer contract: an AP voucher was entered against the contract with an incorrect deptid. The voucher was cost collected, the bill created and invoiced, then the AR item created and an AR payment applied.

All have the same incorrect deptid as pulled from the AP voucher. Then, a $0 AP voucher was created by the user to correct the deptid, which was cost collected into Billing but never sent to AR because it's $0. Our question is - how can we correct the deptid? Is a $0 direct journal the only option?