I have never used eBay, so maybe this is a stupid question... by why in the world would you have sent your credit card number directly to the seller?
But again, this is not about trust. Its about the eBay customer service response/arrogance.
What is ebay supposed to do for you? They can't verify the transaction, so it'd be foolish of them to start issuing refunds from their own coffers. They can't force the seller to refund (as far as I understand).
I'm going off-topic about the perceived arrogance. I'm just curious about what you expected ebay to do.