Advanced Invoice matched incorrectly

We created an advanced invoice (voucher type I). Which debits Prepaids and credits AP. Then we paid this through our normal payment process (voucher type U) which relieved the AP. However, in that process we also matched the advanced invoice to this payment transaction. So it also reversed the original entry by debiting AP and crediting Prepaids. So there is a debit amount left in AP but the invoice shows as being paid creating a difference between the subledger and trial balance amount in AP. How can I reverse that matching of the advanced payment, so I can apply it to the final invoice that’s due?