6 yr old and his teacher

One of the twins didn't finish his work at school today, so when i got there to get him he had like 45 minutes worth of work to do.. the teacher could have AT LEAST called and told me he needed to stay after. So there i sat with 4 kids at the school... Oldest son's bus dropped him off while i wasn't home.. it was a mess...thankfully he knew what to do.. but still.. he's 7 ya know and not all that trustworthy...... i was pissed at him, pissed at the teacher... and i don't even think poor twin B was screwing off while he was supposed to be working.. he just won't try because he writes everything backwards and he knows he cannot do it the right way, so he doesn't bother... and she's MEAN! We're fairly sure he's dyslexic and the teacher has been told tihs, but she keeps making him do the same thing over and over again... and was getting onto the baby because he was dumping stuff, she refused to let us take the work home... It was just a freekin nightmare i was just ready to kill everyone by the time we got out of there.