These involve practical issues based on the forgeries done by the office bearers for their wrongful gains.
The members may dig out the truth and can take up this issue by making a complaint about the fraudulent activities to the police concerned and also with the registrar of cooperative societies for the illegal functioning of the chairman in that post for the past 13 years or so.
You can list out the irregularities done by the chairman and the secretary in the past with documentary evidences and give a complaint with the registrar of cooperative societies with a request to take suitable action as per law, if the complaint do not fetch the fruitful results you may approach cooperatie court with suit for injunction against the chairman restraining him from functioning as chairman due to the irregularities and the offences he had committed in the past in the capacity of chairman.