This is just FOIA. You don't need any special website or process; just Google [(your state) FOIA] or [(your municipality) FOIA officer]. In Illinois, you can simply email free-form requests for documents and start a 10-day clock on the public body's side.
What you do is: you sue. On my 13th FOIA lawsuit and I have a couple more in the works ;)
Depending on where you're from, it's pretty easy to find a pro bono attorney. In Illinois, the plaintiff's attorneys recoup their costs on a successful win.