it has happened to me as well.
firstly ebay didn't inform me that there is claim against my product which buyer purchased a month ago.
no mails , no case opened by a buyer in resolution center, no call from ebay.
suddenly received a mail on 1st of this month that refund is processed to the buyer and i have been covered UNDER SELLER PROTECTION PROGRAM for this transaction because we have noticed that there is no fault arrived from your end in this case. This credit will reflect in your account within next 4-5 days.
BUT IT'S BEEN 2 WEEKS NO CREDIT, NO CONTACT, NO REPLY TO MAILS, and the worst thing is when i called them up the CS team doesn't even know that i have covered under seller protection and bluntly say they never sent the mail.