Residential people damaging and not allowing to repair shops

we r from shopping centre 140 shops.. residancial terrace is above all shops head.. they park there car on our head.. so there is so many shops has leakage and residancial breaking our water proofing there is also our water tank and colling tower is on tarrace since 45 yrs and it has repair work they had made a garden also on above electric room now residance committee member is not allowing to do such repair work as the entrance of terraces is from residance side where to go for my own thimgs do repair? to whom i have to complain for such losses? hoiw to stop parking car? how to remove that garden? above all they r not allowing to do repair also as our shopping centre is structure become so much weak and s;abs are comming down....