Sellers cannot open cases against buyers. What you did was make a report which is not the same thing. The message you rec’d from eBay is the only document that is generated from your input. Like the other poster noted, eBay will not inform you of any action they may take. They may take no action. But the report is there if the buyer makes a habit of it.
Since the buyer has opened a case against you for Item Not Received, you only have a short time to respond with the tracking number uploaded into the case. Otherwise, the buyer may prevail.
When a buyer cannot locate a delivered item, i tend to believe it was misplaced, lost or stolen rather than report a buyer for making a deliberate false claim. That is because a scammer is going to know they cannot win a case when the tracking shows delivered. So it is more likely the buyer is telling you honestly they don’t know where the package is.
The seller is under no obligation to refund or replace in such a case, but can sympathize with the buyer and offer advice on how best to locate their item. That is just good customer service. Did you reach out to your buyer? What happened? Had the buyer behaved in a way prior that a shadow of doubt was cast over their veracity? What prompted your report?
