Try and fix the problems yourself. If the problems are fixable, I'm sure you have insight into how to fix them. There's obviously something wrong with the situation.
If you can't fix the problems, leave. Don't fall into a sunken cost fallacy. Sometimes losing time and/or money is just a part of doing business. You took a risk. Risk is a part of life. But you should also learn to recognize when to cut losses and move on. You should sit down, decide upon what it will take for you to leave the company, and stick to the decision if it comes to pass.
If you can't fix the problems, leave. Don't fall into a sunken cost fallacy. Sometimes losing time and/or money is just a part of doing business. You took a risk. Risk is a part of life. But you should also learn to recognize when to cut losses and move on. You should sit down, decide upon what it will take for you to leave the company, and stick to the decision if it comes to pass.