Hi there!
Look, it's probably not a HUGE deal in year 9, but my advice is to just confront your teacher about it anyway, since it is clearly upsetting you (understandably). There's no harm in asking your teacher about any discrepancies etc, and making sure what you can do to ensure you get higher marks next time. You never know, they might even realise they've made a mistake with your marks and will rectify it!
If you feel that there is an OBVIOUS and perhaps biased difference in marks, then there's no harm with asking your head teacher for some guidance/help. I think it's a great idea taking your education into your own hands from as early as year 9, so don't be afraid of approaching your teachers - it's the kind of attitude and mentality you'll want in years 11 and 12 anyway, when marks and ranks are so competitive - so why not start early
Best of luck with everything!