The same class of problems (questions regarding account balance, money taken out but BTC missing, support went dark) happened earlier this year and there was another front page conversation: https://news.ycombinator.com/item?id=5427985
Sadly, it seems that the key takeaway (the importance of customer support) was lost upon the Coinbase staff. Based on the last response, its clear that they have not learned their lesson.
I recommend pulling all money and BTC out of Coinbase before the next crisis. And I say "next crisis" because there is no indication that steps were taken to rectify the underlying issues here. For example, as speculated in both threads, do they need to move off of MongoDB?