Add:
As per the link you quoted:
As you mentioned, the first box is used ONLY for China to North America (US and Canada). Whereas the second box is used for China to Europe flights--- where they didn't even mention the rules in regard to flights within China/ Asia/ Australia....
I have to admit this information from CZ is very confusing, which potentially could (or already has) mis-lead a person thinking that he will be charged only a couple of hundred bucks for the excessive weight/ pieces. Personally, I do find that you were being charged to the "maximum possible" rate--- combinations of "Excessive Pieces" + "Excessive Weight" + "Excessive Sizes"
But still, I don't see anything wrong in here (but I can understand how frustrated you were at the check in counter). Once again, sorry to hear about your sad story, and let's just say: it's a good lesson learned!!
Thanks for sharing your story with us~~