Agreed with the above post (Bulletzone)... although I'd have to say, the formal complaint procedure could take a long time to get to the right person within the right time scale...
Considering that, I'd encourage you to request your parents to speak directly to your head teacher and get this stuff sorted within the next day or two... if he/she cannot, then speak directly to the teacher in question. Need to avoid the bureaucracy of the school since exams are right round the corner.