How to apply Credit/Debit memo to a Standard Invoice

Hi Guru's

I Need one more advise regarding Credit memo in Payables. I.e  Say example, I have raised a Invoice worth 5000. Now I want to apply credit memo woth -1000 to that concerned Invoice. when I create a Credit memo, After filling all  the header Information  on the invoice work bench for credit memo & then directly clicked on correction tab, then i have selected the Invoice which I want apply the credit memo & then I made payment for that credit memo via payment work bench with Refund type.

  After that when i query the standard Invoice to check the balance, then the balance remains the same i.e 5000. which means credit memo didn't reduce the balance of standard invoice.