When you work as an employee for someone else, you run the risk of being terminated or demoted at some point. If you are demoted without notice, you could be frustrated because this often leads to a cut in pay or fewer work hours. Depending on the arrangement you have with your employer, there might be nothing you can do about it.
If you have an employment contract, it might prevent your employer from demoting you without notice. For example, the employment contract could state that you have a certain position at a specific salary for a defined period. Once that contract is up, then your employer has the right to demote you or renew your contract. If you are demoted with an employment contract, then you might be able to take legal action against your employer.
The majority of workers are considered to be "at-will" employees. An at-will employee works for the employer without any specific contract or provisions. With an at-will working relationship, either the employee or the employer can terminate the relationship at any point. This means that you could quit or get fired at any time without the need for notice from either party. If you do not have a specific employment contract, this is the type of employee that you are.
When you work as an at-will employee, your employer has the right to demote you. As an at-will employee, you do not have any way to prevent getting fired or demoted. Your employer has the right to give you any position he wants. When an employer demotes an employee, he does not have to provide notice, either. You could come into work tomorrow and find out that you have been demoted by your employer after working there for 10 years.
If you are demoted, it can be difficult to get through the situation financially. While you might be considering legal action against your employer, your best bet is to look at your other options. If you have other career options, consider them as an alternative to your current job. Otherwise, you will simply have to tough out your current situation and possibly get promoted again at some point in the future.