Discipline monster san

My san san is very unmanageable this morning. Very cranky mood. Throw tantrum and scold almost everyone in the house. Just because of a piece of cake. She wanted to 'steal' little june piece of cake for breakfast when she finish her share, so we say no. And she start to scream and cry. And scold us. Say we naughty and stupid. And say throw me into dustbin. Of coz she say in chinese. ＂妈妈坏蛋，爸爸坏蛋，姐姐坏蛋，怡君坏蛋。＂＂你很stupid" etc.so i cane her. Many many many times. More than 30 strokes. And she keep challenging me, say not pain. So i cane her more. And she never learn from mistake, one day can repeat this kind of thing a few times. The two other sisters never create this kind of problem for us. And she scream and yell for very long. The pitch so high, i think she has reached the highest pitch one can have. 我的心也很痛，但是不打不成器。if dun teach now, she is going to be even more difficult to handle in future. Now only four years old already 无法无天，need to really discipline her properly.