Credit note vs dates invoiced and taxes

Credit note vs dates invoiced and taxes

We have 15 clients (15 invoices) that paid 775$ in may 2012.
Taxes related to thoses invoices are paid out each quarter (in this case June 30, 2012)
 
As of October 2012, we agreed to credit 255$ from those invoices.
We applied 15 credit notes.
 
However, the credit notes modify invoices for which taxes have already been paid. Changing our taxes report and and creating problems in past reports.
 
Is it possible to have credit note set to reflect a refund in October 2012, therefore applicable for our Q4 tax report of Dec. 31 and not modifying our Q2 taxe report.
 
Thanks
 
Richard matte