Year - end adjusting entries

SUGGESTED

In a clients year-end adjusting entries there was a couple of duplicate postings for vendor invoices so the adjusting journal entries the accountant gave to correct this is to DB the A/P account and to CR the Hst paid & the Purchases (corresponding expense account)  .... but how does that clear the unpaid payable sitting there - I cannot somehow hit the vendor with a journal entry so in the vendor aged these invoices are still showed unpaid ... can we not just reverse the invoice ?