Should I go to the detention?

i've been given my first ever detention (im a geek i know) but its for being late and the only times ive been late are when the form tutor has done the register to early but i was still technically in school before the bell and it was only 3 times in the whole year. i know for a fact there are 3 or 4 students who have been late about 5 or 6 times but arent being punished and i dont think its a coincidence that they are like the highest achieving kids in the year so they are just getting away with it cos they are clever. im on both the school councils, im a prefect, i write for the newsletter, and i help out in my own time, do you not think ive already given enough of my time to the school? do you think i should stand up for my rights and voice my opinion? without meaning to boast, i am quite an et to the school and by punishing me over something i havent done they are completely ruining my trust after everything ive done for them. please dont bother leaving hateful stuff here, it doesnt help.