My personal experience is that the first tier of customer service people aren't that helpful either. Probably not their fault - I suspect they are not empowered to do much and have to make a judgement call as to when to escalate to tier 2.
Now the 2nd tier customer service people I have found to be extremely helpful, empowered and able to get things done and make decisions.
I suspect that because you had issues with the "ED customer service" people you were sent directly to "tier 2" customer service.
I suffered with poor customer service during most of the oil pump fiasco. After many weeks of frustration I got elevated to a nice lady named Liz who was helpful, informative and made things happen quickly. As soon as she got involved I started getting follow up calls from my dealer's service manager and she followed up by calling me everyday until everything was resolved.
Current: 2013 Tesla Model S
Previous: 2013 BMW M5; 2012 A7; 2011 S5; 2011 X5M; 2010 750Li; 2009 M3; 2008 X5; 2003 M5; 1998 540i 6 spd.