buyer didn't respond after requesting a refund

[letitia407]

A customer requested a refund/return.  I offered them a partial refund which would allow them to keep the item instead of returning it.  The buyer didn't accept the offer or respond by the date set by Ebay.  Ebay said that the refund request would be closed on a certain date but it is 7 days past that and the request is still open.  This has affected my Top Rated Seller status.  How do I get Ebay to close the case since the buyer didn't respond?