Oh I've remembered one from ds.
He'd scribbled science off his timetable in year 9 and kept saying he hates the subject - odd because he loved it previously. Turned out he hated the teacher.
After a few weeks I rang and said there seemed to be an issue and could she tell me what was going on? (I work in education so know there's always 2 sides - or not in this case!)
Reply I got was ds was a PITA to have in class and responsible for 50% of all issues "because he has poor social skills and his wiring is illegible"
I will point out dear readers my ds has a physical disability and autism and and EHCP to support this! Kindly suggested we spoke to senco and arranged support but she seemed more keen on him just writing more clearly and improving his social skills or he'd fail!
Next day is Friday and ds comes home from school broken hearted. The kid who school staff know bully him had given out books in science and hidden ds. When ds asked where his book is this bully and his mates all offered to help and found it under a front desk and said ds threw it there. Ds didn't and wouldn't and the kids on his table all backed him up.
Anyway I get home from work Monday to a voicemail which a gleeful voice that ds had failed to attend his lunchtime detention and therefore she'd made it after school.
Now ds had taxi due to being at out of catchment school named on his EHCP.
Que panic from me to school who inform me he's in his taxi as his keyworker saw him off and ds arrived home at this point.
Ask ds why he didn't attend his lunchtime detention today the science teacher set - to be told by ds science was after lunch!
I check voicemail and it's been sent at 11.18am 
So I emailed HOY with recording of voicemail, time it was sent, that science was period 5 and previous conversation and just asked him if he could find out what was going on?
Phone call at 8am following morning to say no detention and moving science groups. (Didn't say he thought teacher was being a twat but jist was there)
She wouldn't even look me in the eye results day when ds collected his gcse science results - he got double 9 