Here is one trick to get some attention. Tweet your concerns on @coinbase. As the tweet will be public, they will have no choice but to reply immediately lol. Coinbase is already getting some bad reviews from Bitcoiners who are active on Twitter, and they wont be needing more.

Try it. It worked for me once, but with Poloniex.

With that said, what made you use Conbase in the first place? They are incompetent.