You're obviously somebody working for a dodgy school. Poor work quality does not justify poor treatment; especially when contracts and laws get broken. Even the shittiest of teachers are entitled to these most basic of rights, anywhere in the world. If your employees aren't performing, you can try to motivate or train them, follow legitimate disciplinary procedures or even dismiss them, but deliberately treating them like shit is very risky; even in less developed nations where the concept of unfair dismissal doesn't quite exist.

From what I can see the problem would in that case, lie not with the individual teacher but with the HR staff. They probably failed to hire to suit their organisation's needs, failed to make the organisations expectations clear to the staff and failed to provide adequate training and support when it was needed.

Regardless of Brigitte's teaching ability which could be either good or bad (how the hell could I know without seeing her teach?), the simple fact remains that the employee was left feeling unsatisfied, they've failed to retain staff, they will have to spend more time and money recruiting staff to replace her and it has negatively affected the reputation of the organisation.

So it now seems that online schools, just like Chinese training schools are being run by people who just haven't got a clue...