Kerry - I'm sorry things didn't go so well. Before we actually got a grade skip for DS, we were also given a whole bunch of reasons why the school wouldn't do that. We had success with having the school fill out an IAS form, and I can't remember if you already did that with this school and the first skip? It gives them an objective way to monitor whether a skip would be appropriate or not.
We also argued that the differentiation would be so much easier with the skip, and it was, though not perfect. (We have had 3 schools in 2 years, so we can sort of relate to the moves.) Is your DD in DYS? The family consultants can help with ideas for what to do for your DD. Also, there is s free service for educator's here, where they can join e-lists or get access to documents explaining how to help HG kids:
http://www.davidsongifted.org/edguild/I think you gave wonderful responses to their arguments. It's hard to speak clearly when people are saying things that don't make sense. But at least they admitted that they don't get your kid; this is your opportunity to help teach them, and hopefully they will respond.
I agree with Edwin - keep trying. We would have been in a similar boat, likely asking for a second skip, if an opening in a school for HG kids hadn't come up midyear (45 miles away). Good luck!