True, but even Amazon is sometimes a pain to deal with if the package isn't delivered but claims to be, especially if it is a 3rd party seller. You have to weed through a bunch of automated responses before actually being able to contact someone, I'm sure they set it up that way intentionally.
I prefer dealing with Amazon, but for some things (especially used or hard to find parts) ebay is pretty much the only way.
If the OP paid through Paypal it might be worth filing a dispute with them, or even your credit card. It's a major PITA, but usually yields results.