Never escalate to ebay as a seller.

The case will be closed automatically if the buyer does not escalate it. New buyers tend to open a case on a whim, then back down and do nothing. Don't send any more messages to the buyer if they don't reply and just wait for the case to close.

In my experience, if the buyer does not respond, it usually means they have backed down. Only once in my history that a (brand new) buyer opened an INR case the first day he could on an untracked item, I asked him if he would mind waiting a little longer as AP is sometimes late, he didn't reply. Then the very first day he could escalate the case he escalated and I received an automatic defect. But that's a horror story and horror stories don't happen everyday.