Ebay is a huge market. Not one man has the only item of one thing. When the seller asks you if you want your money back, you say yes and buy the item from somebody else. If the seller refuses, eBay has the proper tools to help you out of a hole. Sure...you may have to wait a few extra days by taking this path, but you don't lose your money.
I started out by buying small things on eBay. 5 dollar purchases here and there so if I were to get ripped off, no big loss. It was only 10 bucks. After a few purchases you can get a feel for the seller and work with that seller. I have about 6 sellers that I buy from on a regular basis. 2 out of those 6 sellers I have formed a 'relationship' with and send random messages back and forth about products. I also save all e-mails from each deal for 30 days after I receive the product.
Basically, take the money and part ways. Buy it somewhere else. Just be smart. Don't worry about offending the seller because they fucked up when you accept a refund. It's your money.
The Distance Between Courage & Stupidity Is Exactly Nine Millimeters