(Disclaimer - the following is aimed at no one in particular, but simply offered as advice that could benefit us all a little.)
I wish everyone complaining about getting screwed would realize that you have more of a say and impact than you think - and by accepting these bogus decisions and policies and simply venting here, you are only enabling it to continue.
I've had final decisions reversed, had buyers made to pay for bogus "SNAD" return shipping, had negative feedback erased, and more. You simply have to be patient and persistent - and let eBay know that the situation is unacceptable. First make an honest effort to work it out with the customer. Have the evidence available showing that you tried to provide your own excellent customer service, without being cheated. Then escalate the case to managers. Insist on it when they say one is not available. Call back when they hang up. Put in the time. Explain your situation over and over. Document every call and conversation. Reiterate how long you've been a customer, and how terrible the customer service experience you are getting is - all without being a jackass. Simply make your problem their problem, and they will usually become more willing to help you get rid of it.
It's rare, but you can even occasionally find a human that cares enough to see the situation the way it is, and do what is right. Yes, they have the power to do that. There is no "buyer always wins" policy. Certainly that is the eBay culture that has developed in the past few years, but each case is handled individually in the end - by humans. Do your part and make them act like it... or else don't complain. Maybe it's not worth the effort to you, and maybe it shouldn't be this way, but deal with things the way they are to the best of your ability and you'll find a lot more satisfaction.