Very sorry to hear what has happened.
It may not help that schools have been told not to change the headteacher summary sheet in response to parental pressure.
(You could legitimately ask for any inaccuracies to be corrected, but it's not so easy to ask for something that is "better").
..... writing to MP, County, legal action possibly .......
None of these measures would get you anywhere, I'm afraid. You'll just be told to take your concerns to an appeal.
(They may omit to tell you that, if you've already been through a review, you'll have the hurdle of 'fair, consistent & objective' to overcome.)
The grammar schools are probably full of academic boys who are chatty and lacking in concentration!