Thats ridiculous. If she believed that you were not trying enough (which is entirely possible even when receiving an A) she should have spoken you about it first and not used a technique that detrimental to your current grade. I had a teacher lower my grade for not smiling enough once, i understand your pain.
just a few, it was the principle of the matter. I sit in the same classroom for 4 hours a day for five days a week to pass your class in 4 weeks (its a block plan as opposed to semester) and you expect me to be happy the entire time. No.
I did actually, i just thought you meant by taking that 15% away, it lowered the grade of the test, not your average. However, I do see what you mean now. I would like to add that it's not mentioned whether the A refers to your test or your average in the class, so thorough reading had little to do with it.