Partial Refund

The seller sent me a defective item and I asked for partial refund as it would be such a hassle to return the item. After I opened a Paypal

claim, the seller agreed to partial refund but asked me to close the claim first saying their finance department cannot issue refund when there’s an open claim. So, I did. However, it’s been months since the back and forth discussion and now they’re saying there’s issue with eBay which prevent them from giving me the partial refund.  I cannot find instructions online where I can ask for partial refund apart from just sending an email to the seller. The seller kept saying it’s eBay issue.. Not sure I believe them. I was wondering if I can contact eBay directly with this issue so I can get to the bottom of this. Being in limbo is not great.  Any advice will be appreciated. Thanks!