However providing nicely worded text or email with all the information and references you are comfortable providing have been known to open doors some times.  I would not pester them if they don't respond.  No one knows how they really decide on who to accept and not accept.  Even though I am an established client with many K-agencies, this one new agency is ignoring my text and email, so you are not the only one.  Before everyone starts pestering me with PMs, I do not have any secret password or handshake to get you in with any of these agencies.

Then you could just search.  Oh wait . . .

Same experience. When I call, they ask to fill the form on website for screening. After you fill the form, it's just crickets. No response. I tried couple of times and the same result.

Feast or famine

Your question has been asked by many in the Community with pretty much the same response.  I too are amongst the many who have been given the wall of silence.   If you look at the big picture they are only hurting themselves.   Mongers come and go and to loose the potential of new clients is well just poor business.   If a new K agency would open up in DMV area and with open arms welcome all who had the right credentials would be very successful.    It is called competition, something the local elite K agency's need a shot of to remember who puts down the envelope.