eBay

Recently sold an item, and the buyer immediately opens a return because the item states it's not working. I accepted his return and he got a shipping label. He has not returned it, because 3 days later he closes the return, and opens a case with ebay...

I ordered 3 hard drives from a seller, but i'm missing one. How do i open a case for this situation? The only option i have when i open a case is "return". Seller is not responding. Do i have to wait a few days before i can open "not as described"?