To understand what is going on here it is important to read, "Odd Girl Out - The Hidden Culture of Aggression in Girls", by Rachel Simmons.
In it you will find group bullying laid out, from seemingly random personal attacks to attacks by the whole group. And when the victim complains, they are accused of 'venting'.
Male bulling is fairly easy to stop - all you have to do is to stand up to the bully. But if you stand up to group bullying, it only makes it worse.
And this is what I have found here - the more I complain, the worse it gets.