Schoolsnightmare, you poor thing, this must be so stressful and upsetting.
Not an expert, but the thing that struck me when reading your post is whether you are on every possible waiting list? Because if your friends are getting their 2nd choices, they will be relinquishing their sixth choice, freeing up a space there, so if you are on that list you will move up one. But maybe their sixth choice is the wrong gender or faith or something for you.
You probably also have this covered but I think you said before you live in London? We do, and in a bit of a hole for secondaries, and the advantage London gives is that within, say, an hour's travel, and considering all the different forms of transport, there are a lot of schools, perhaps including some where distance is not the main criterion. Children from near where I live routinely go to schools in the three closest boroughs and probably another four on top of that, less commonly. I know it is clutching at straws. Around here, local councillors seem to pitch in sometimes (not to make a place come free, but to make sure families in this position are given access to the people in the LA that really know what happens, that sort of thing I think).
Fingers crossed for you and your boy.