Well the problem in my GF's case is that there's no more room for adjustments, the top strap is as tight as it goes but it would need to be tighter for it to be comfortable :/
Maybe it can be worked around by putting on a beanie or something, but if they only made the velcro strip a bit longer it would not be an issue.
The best hope would be if someone will start selling alternative straps.
Have you tried moving the back strap lower? And use the other foam padding? My girlfriend had the same issue. First I helped her set it up but in the end she found herself a position with which she is comfortable.