You did have a valid reason for the return.
You rightly opened a case for item not as described, as per the rules of eBay's 30 day MBG, Money Back Guarantee policy.
You then wrongly, closed the case !
Once a case is closed it cannot be reopened with eBay.
For that item, you can turn to your payment provider for hep with your refund.
If this was 2 separate purchases, you can still open a case for item not as described for the other item, escalate on day 4 if not refunded beforehand.
@bettie_bee