I know it's hard for people around here to believe, but 65-75 is a good score. I know people this year who have gotten ENTERs under 30, somebody even got an ENTER lower than 10. It's no reason to repeat.
Reassess your options and look through the VTAC guide for courses that may interest you which also have a realistic entry score (if it's a bit high, still apply - lots of people get into courses on the fringe). Think about the kinds of subjects you could do in the course. I agree that a Bachelor of Arts would be good, you'd quite easily get into Arts at Victoria Uni. Otherwise, you can apply for business courses at TAFE.
I have my VTAC guide open right now, and there are actually a heap of courses you can apply for! Try to imagine yourself in a certain degree program, see if you could get used to the idea, consider that it's likely that you'll do well in any uni course and be able to transfer into another. Uni life is also much better than how full on VCE is. Depending on your degree, you may only be at uni for 4 days a week. I would never ever ever go through the tedium of VCE again, but obviously it's your choice.
And I second that if they did make a mistake, you really need to do something about it ASAP. Mistakes happen and you can appeal (they just like you to think that you can't). All sorts of things go wrong. In the very least, it will give you peace of mind.