Seller Return- change partial refund offer

Hi 

 

Buyer requested return as they claimed item was not as new (it is, just damaged box, but whatever).  Using the ebay returns flow, I offered the buyer a partial refund and to keep the item.  They then contacted me through Messages to say they would accept a slightly bigger partial refund to keep the item and close the case. 

 

I cannot find any way in the eBay seller console to change the partial refund offer.  If I go to the refund status it just says it's waiting for the buyer to post the return.  If I go to the regular 'refund' screen it says I cannot offer a refund as there is an open return. 

 

How do I resolve this?

 

Thanks.