The company hired people behind my back and didn't say it was illegal to fire me?

It's not illegal for the company to recruit people behind my back, but it didn't say it's not illegal to fire them.

From a legal point of view, any position, the company has the right to decide whether to recruit, regardless of the employees currently working in the position. What you have to do or can do is to negotiate with the company at this stage. Your question of staying or not.

Recruiting people behind your back may really mean quitting you, but it's not because you worked hard and didn't make mistakes. Because of the fierce competition in shopping malls, sometimes it is not only required not to make mistakes, but also to have excellent performance, which is unique. From this point of view, people with 60 points may not be so useful in the competition, and people with 80, 90 points or even 100 points may be needed.