please don't make major decisions based on incomplete info. Plenty of people take the August MCAT and get in to med school. One anecdotal story does not provide a complete picture. I took the Aug MCAT and had interviews at 12/15 schools plus multiple acceptances and a full scholarship offer.
Yes, it is a disadvantage at rolling schools esp the highly competitive (e.g. UCSF, Mayo, etc.), but for most of us it is much more important to get a good score the first time round. Also, you are sabotaging yourself if you wait until the end of October to submit your AMCAS; you need to turn it in before you get your MCAT score, although this means you can lose a lot of money if you end up with a crap score.
Re the half-refund - that is what they do, keep half of what you paid. That's why it sometimes makes sense to take it in April and void, just for practice.