Then you can't be surprised that it's going with your company pretty downhill. If you do not start doing anything immediately, you will have to declare bankruptcy very soon. The mistake is mainly in humans. You produce quality products that are of great interest. However, the staff makes one mistake after another. You are losing regular customers and you are unable to get new ones. You must strive to create powerful teams that will deliver higher incomes. Every person has some strengths and weaknesses. It is necessary to reveal them and derive the appropriate consequences from them. You can start using your strengths for the benefit of your company immediately.
Do not dispose of money unnecessarily for inefficient training
The Personnel section of your company has problems. There are no skilled people working here. Admit it. You've been fired a few times for totally useless and inefficient training. They did not bring anything to the staff and unfortunately their performances are still below average. It will be best if you prefer to pay a professional externist who has a wealth of experience in evaluating employees. The information obtained must be analysed and the appropriate conclusions drawn therefrom.