When were Chinese characters cut?

First, I don't quite understand your question. What is "cutting Chinese characters"? Aren't we using Chinese characters now? Chinese civilization has been passed down for more than 5,000 years and has never been cut off. However, the civilizations of Egypt, Greece and Babylon were cut off.

You want to talk about Oracle Bone Inscriptions, right? Oracle Bone Inscriptions is the script of Yin Shang, so it is called Oracle Bone Inscriptions of Yin Shang. It is a divination written on tortoise bones, which generally divines the fate of the country, the victory or defeat of the war, and whether the agricultural production is smooth.

Oracle Bone Inscriptions, originally called keel, was mixed with Chinese medicine to treat diseases. Later, it was found that there were words on it, and Wang bought them in large quantities. For this matter, Yu's article is called "Wen Bu Yin Ruins", which gives a very detailed and vivid introduction to this matter. Please have a look.