Discrimination

How do I go about making a case for discrimination on my kid who has autism with server anxiety and other special needs. 1 She only had 11 hours a week at school for a year
2 I was told she had no more school from May the 24th and only go in for exams but all her class mates had extra lessons before each exam.
3 didn't give her her exam timetable on the Friday before her exams started. When everyone else got there's weeks before.
4 They told her she did not have to take the exams
5 would not let her go to her leavers assembly for having an argument with a teacher as she was so stressed and on her way to an exam.. I wrote to the governors but got no response.
6 told me and the autism advisory teacher they know it is due to her autism and anxiety but it's a punishment when we challenged this they can't punish her due to her special needs they said she needs to learn actions have consequences and would only let her watch it on a laptop. There was actually so so much more than that but this was all in the last few months. Any advice at all would be much appreciated.