Maintenance charges by builder

Our society is unregistered. We have ad hoc committee. OC is given by the builder. We pay maintenance charges to bulider. Since bulider has not completed some of amenities work stated at the time of purchase, some members of our society have not been paying maintenance charges and there are huge outstanding . Due to this apart from water and electricity builder is not providing other facilities. We are facing problems. Those flat owners ( they are not residing here) are saying they will pay maintenance once society will form. How long these owners can not pay maintenance. What builder can do legally? What ad hoc committee can do? Please suggest, because of some all are having trouble.