The buyer has received the item, but the item is damaged or it does not match the listing description.
In the case of a Significantly Not As Described (SNAD) item, the buyer has a couple of options, including returning the item and giving a SNAD-related reason when submitting the return request, or possibly keeping the item but asking the seller for a partial refund.
If the seller does not address a return request at all, the buyer can escalate the return request into a case, and eBay will automatically refund the buyer and bill the seller to recoup that money if the buyer wins the case.
Although it is not recommended, a seller has the option to decline a buyer remorse return request. The seller also has the option of declining a SNAD-related return request, but for this type of return request, the seller must be prepared to provide some proof through a Return case that the item matches the listing and is not a SNAD item. The Post-Order API provides a programmatic way to submit and handle return requests.
For additional information, refer to: