Just out of curiosity, in what manner did you request help from the phone support?
I've found that if you call them already pissed off and blowing steam, they will be less likely to help you. Remember, there is a
person on the other end of that phone, and they are not responsible for your unfortunate situation. Apple is, and these customer service folks are your link to Apple. Be nice, because they aren't going to help you if you disrespect them.
Calmly explain your problem, tell them you've done everything imagineable to fix the problem and don't want their phone line tech support, and that you just want them to fix your computer. Explain to them how ridiculous the situation is (as calmly and politely as possible), and ask them if there's anything they can do to help you.
Fact is, they can do a
lot to help you, but they've been ordered to avoid it if at all possible. Since you don't have AppleCare, you are officially a second class citizen when you call Apple. It's unfair, but that's the reality. If you bring this point up (again, calmly and rationally), you might just get somewhere.
Also, something else you can do is try to think if you have any friends who have found themselves in a similar situation with their Macs. Did Apple resolve their problem satisfactorily? If so, tell them that. Tell them that your friend had a very similar problem, and Apple went above and beyond to fix the problem for him/her. This usually catches their attention, since they don't want to appear discriminatory.
I know it can be tough to be put on hold for an hour, threatened credit card charges, and told that you have to pay shipping, but don't let it get to you. Just soldier on and keep telling them how ridiculous it is to expect that of their loyal customers. You just might get somewhere
Good luck!
(oh, and for the record, I've spent far more than my fair share of time on the phone with Apple...but every single issue I've ever had has been resolves satisfactorily in the end)