There is no direct way to "get a listing" in the Google Directory.
Google takes its data from the Open Directory Project, which is a directory run by volunteers. Google is one of many sites which use the data.
Sites are added to the Open Directory by editors. There are many ways to bring a site to the editors' attentions - and the one you are familiar with is the "Suggest a Site" link.
However, this does not give any sort of priority review.
So it sounds like you have done all you can - there is no priority review process available, nor are there plans to provide one.
Patience would be my recommendation