Without the requested information, I can only provide you with general information, which hopefully will still be useful to you. First of all, I am sorry to hear about the issues you have experienced in your situation.
Legally, you an try and get a restraining order against her, but practically, it may be difficulty to enforce. It is one thing to have a restraining order against someone in society, another thing against someone in work, especially as the employer ha control over what they do, where they work, who they work with etc. I would not recommend it to be honest, not in these circumstances.
In terms of challenging the company, you can initially raise a formal grievance about it.
You can get a detailed explanation of the grievance process here:
In summary, an employee is expected to submit their concerns in writing and send them to their line manager, or whoever is nominated as the person to send grievances to under an official workplace grievance policy.
The complaint should include details of what the grievance is about, any evidence that may exist which is relevant and also what the employee wants their employer to do about this issue.
Once the grievance has been submitted, the employer is expected to arrange a formal grievance hearing, inviting the employee to attend and discuss the nature of their complaint. The meeting is also as an opportunity to ask for further clarification or information, as required.
Following the meeting, the employer will take time to consider all the issues and evidence and then make a decision, communicating it to the employee. If the outcome is not to the complainant’s satisfaction, they can appeal and get a second opinion from a different person assigned by the employer to consider the appeal. Once the appeal is also completed, that brings to an end the formal grievance process and there is no option to escalate it further internally.
As to suing them, you cannot just make a claim for anything yet, the only way to challenge the employer would be to wait to be dismissed and then claim for unfair dismissal, or resign because of what has happened and then claim for constructive dismissal. You do, however, need 2 years service for either claim so it means that if you do not have that, you are left without many rights to challenge them.