Such a high amount for charging sounds weird, especially since the user had some free Supercharging credits.
CnEVPost's article includes images that show 1,923,720 kWh (almost 2 GWh) of energy, at 2 CNY per kWh.
According to the estimations - it would be enough to fully charge the 2020 Tesla Model 3 Standard Range Plus (0-100%) about 32,000 times.
The extreme bill happens to be an obvious mistake and according to further info, the user received a response from Tesla customer service, saying that "there was an error in the back-end systems of some vehicles." It will be fixed.
Nonetheless, it means that there might be more than one user that faced a shocking notification and was mistakenly banned from Supercharging.
We don't know what caused the issue, but according to the article, Tesla was tweaking the Supercharging idle fee to improve the utilization of the charging stalls. The new idle fee in China is 3.20 CNY per minute (6.40 CNY if the station is 100% occupied).
For reference, in the US, the idle fee stands at $0.50 per minute ($1.00 if the station is 100% occupied). In many European countries, including Germany, the numbers are the same but in euros (€0.50 or €1.00 per minute).