Hi Okihara, that does not sound like a pleasant experience and I can definitely sympathise. I can only speak from my limited experience having just gone solo (greatest feeling ever) but as a fellow student I thought I would chip in even if we are drifting off-topic.
I'm learning at YLIL and have only had a positive experience thus far. I have my lessons booked one month in advance so I always fly at the exact same time every week with the same instructor. I really wasn't making much progress until I committed to do that. I find the weather is still in the morning so I always fly then. I do not believe I have had a lesson cancelled due to weather this year. I do not feel in any way like I am being treated as a cash-cow and find the people working there very friendly and supportive. There is no pressure to pay in advance unlike another flying school based at Moorabbin, the briefings are not charged if you don't fly due to bad weather etc.
I don't know what school you're learning at but I'd really recommend giving YLIL a shot if you can drive out there.
With regard to the exams, I have only done my RA-Aus pre-solo exam but there was no charge and I was talked through all my mistakes etc. They have a great online system which I believe one of the FIs has developed as a bit of a pet-project. Great to see!