How you deal with a bad employer will often have a great deal to do with exactly what makes the employer “bad” and who within that company is the source of your problems. You would, for example, likely deal with the situation differently if it is a specific manager who is poor, rather than company policies that you simply do not agree with in practice. Overall, however, you should be sure to not violate company policy in your actions, as doing such may result in termination of your employment. You should also consider all the avenues open to you in dealing with a bad employer, such as formal complaints, legal action, changing locations, and potentially ending your employment.
What makes for a bad employer changes a great deal and is often a subjective opinion of an employer by his or her employees. One of the first things you should establish when dealing with a bad employer is if the problem you have lies with the company itself or with a specific manager. For small companies these may be the same thing, but in larger corporations you may have issue with a single manager among hundreds or thousands of managers.
If your problem is with a bad manager, for example, then you likely have more options available to you than if the company you work for is what you would consider to be a bad employer. You may want to start with human resources (HR) representatives where you work or within the company for which you work. These people are typically trained and enabled to deal with situations regarding poor management. If you simply have a disagreement with your manager, then you may not be able to resolve that issue in a way you want.
Your manager could be doing something that goes against company policy, however, which could open the door for you to take more action. If you go to an HR representative and can demonstrate how your manager has not properly followed company policy, then the representative may be able to work on resolving the situation. You may need to change tactics, however, if you work at a larger company and you simply do not like your manager. Though many managers may be viewed as replaceable by the company they work for, this will usually not be done based purely on a disagreement with a lower level employee.
If the bad employer you are having issue with is the company you work for, then you may need to consider simply changing jobs. You may have problems with the basic company policies or practices of where you work, and if that is the case, then you may simply need to find a new company to work for. If the policies you have a problem with violate local labor laws in your area, however, you should consider contacting local business regulators and administrators to deal with your bad employer in a legal sense.