My first time out, I didn't receive a reply either. At the time (this was quite a few years ago) I didn't have a solid sense of what the different lineages were or how they differentiated themselves online so my followup ("Hey, why haven't I heard anything back from you?") email went to outercol.org from whom I did eventually receive a reply which included a Student Exam. The exam took longer than expected to complete (life situation changed pretty dramatically right around that time) but I did eventually submit it, to which I got the standard, "We've received your exam, we're totally overwhelmed in life but we'll be in touch once we've had a chance to review it," and then nothing. I suppose I could take this as them passing unfavorably but, without any response whatsoever, who knows?
My next step was to knock again at the door of ordoaa.org by sending them the completed Student Exam with the understanding that it wasn't issued by their particular lineage but that it should, at the very least, demonstrate my readiness to submit myself to whatever their Student Exam may be. Still no response. I recalled at this point the meme of needing to knock thrice before the door would be opened so I submitted one more application, this time by mail. Again, no response.
However... in the process of making sure that all my t's were crossed and i's dotted for that third and final knock, I happened upon another door that opened almost immediately. It is not a direct entry to A.'.A.'. but it will get me there eventually and, in truth, is allowing me to work on some things that I likely never would have had I gone straight into the A.'.A.'. path.
So, I'm not going to repeat the old "teacher will arrive when the student is ready" post hoc ergo propter hoc chestnut because, honestly, I look back on where I was and I think I would have been ready at any point in that limbo period to engage in the work that ultimately opened itself up to me. My best evaluation at this point is that there just aren't enough Neophytes out there to take on everyone that wants to be a student so, justified or not, the door isn't answered as often as one would like. But, I will say that there are doors and they can be opened. It might just need a bit more of a creative approach to get the doorman to wake to your knocking.
Keep trying, though. It's worth it.
Go in all ways contrary to the world.