Help with a teacher!?

I am in year 8 in an Australian high school. This teacher which is usually quite fair and she is an extremely good teacher has just put me on a behavioral contract. If you don't know what this is, it is a contract which you must hand to your homeroom teacher and the teacher who issued it to sign it to see whether the Childs behavior has been good, and if it isn't (as in if the child does the tiniest thing wrong) then the school is entitled to give this student a very harsh punishment (usually Friday night detentions). These contracts are very hard to get and only the naughtiest gets them, yet I landed myself one. I am a very competent student that talks very rarely and has only ever gotten one detention in my two years at this school. The punishment that comes along with getting the contract (which is 5 yard pick ups during lunch) I will take fine, but not the contract, the only person in my cl to get one was caught smoking out the front of the school at lunch and then I got one for talking like twice along with one other who is also a very good student. I need some ideas to get off this contract or a way to approach the teacher about why she did this. She is a very strict teacher usually very fair. Thankyou vey much in advance.