Not sure about the other sites but they might have some relationships there. In any case I suspect the two key points in your post are:
1) new and only a couple of K-girls and
2) most prominent agency

My guess would be that the top of the hill will support the top tier clients so until you've established yourself as an A List type client they are not answering your call just yet. So even if you don't want to join the other sites (if they non-review sites no problem saying who they are) you will want to show a bigger commitment to both K-Girls and hobbying or it's just not worth the Agencies efforts. Sounds like it would be one everyone wants in with if it's the most prominent.

Might mention the actual agency and someone here from that side of the country might have some more advice. Still, you're getting a response and further instructions which is more than most get so maybe you're doing things right and you just need to keep practicing the three P plan.