How to change the account of Invoice after Payment??

Dear All,
We are facing one issue while reconciliation of AP to GL. Issue is that User has enter the invoices with same Debit and Credit account on Invoice and then pay it by Bank. So the account entry is showing like this :

In AP = Invoice = Expense Account = AA with amount 10 Debit
                            Liability Account   =    AA  with amount 10 Credit

After Payment = Liability Account = AA with amount 10 Debit
                            Bank Account =  BB with amount 10 Credit.


So in the total balance of AA is Debited with 10, in GL and now what to do with this wrong entry??


Thanks in Advance..........