Just adding my tale of support woes.
I've had an incident open since Oct 27th involving a Vox pre-order that still has not been resolved.
Another incident involving books that went missing from My Library/Purchased has slowly made progress, but involves constantly explaining the issue in every email exchange. It took several exchanges before they understood the problem.
With both incidents, the only way I've made any progress was to open a thread on getsatisfaction and update it after each email exchange. My email replies appear to go unread until I mention in the thread that I'm not getting any replies. Then magically, something happens.