@sowseararts Sometimes the advice given by customer service is not beneficial. Sometimes it can be harmful.
In this case, I would be all over the USPS to locate the package. You can call the post office in the buyer's location, or go to or call your local postmaster. The information they have is greater than what you can access online, and they often have important additional details.
When a package is running late, it is helpful to keep in touch with the buyer to prevent an Item Not Received case being opened. (When you referenced the open case, I am assuming that is the INR claim.) If you are calling eBay, it should be to request an extension of the case to give the package a few more days to arrive before you are forced to refund. Then use that time to investigate with the postal service.
What explanation did the CSR give you that entailed the buyer contacting eBay? There is no reason for the buyer to do so. And "doing nothing" is absolutely the opposite of what needs to be done. Once the Item Not Received case is opened, the clock starts ticking towards the refund you will be required to give-- you only have 3 business days to resolve the issue (.ie. give the refund or prove delivery). After that time, the buyer can ask eBay to step in to resolve the problem. If eBay gets involved, they will force the refund if the tracking does not show delivery, and your account could be given a black mark, called a defect. Your Final Value fees are not credited, you will be expected to pay them as a penalty. That is why it is imperative that eBay not step in to fix the issue, that you must do it yourself.
Below is the link to your responsibilities and next steps to take when an Item Not Received claim is invoked. Sorry you didn't get that info when you called CS.
https://www.ebay.com/help/selling/managing-returns-refunds/help-buyer-item-didnt-receive?id=4116
