How to correct a return sales order

Hi All ,

I have an issue where user is created return the sales order for incorrect customer and also there is a credit memo against  the same return sales which is also same wrong customer .

So my issues is how to clear this :

For the credit memo i can create an adjustment ,but for the RMA receipt(inventory receipt ) and COGS  how can i clear this .

Your input is much appreciated .

Regards,

Sugath Navarathna