Vendor credit memo

Please help me...

There is an Accounts payable open item.

First we purchased the goods worth of 1000/- out of which 200/- returned. We have raised the vendor credit memo for 200/- but later we received the cheque from vendor for 200/- so we need to reverse the credit memo which we raised and we reversed once we receive the cheque. Now there is an open item of 200/- in the AP accounts, no balance in vendor account