Issues with promoter

I have a 2 BHK flat in North 24 Pgs. purchased during 2011 and registered during 2015 . We had multiple issues with the promoter from time to time however, consumer case raised by few persons helped us to get our flat along with 60-70% completion of the overall project . After consumer cases have been settled, the promoter attitude again back to previous state . Recently, when I requested to install Grills outside windows and balcony they are not providing me any specific date for last 15 days even after follow up and mails . Even the Promoter was bit rude while talking to me saying they can't give any specific date now and can only do that after they get 3-4 similar orders for the same from the other flat owners . However, I came to know that they didnt clear payment to the Grill contractor and thus the contractor is not working further. At the same time, they are not allowing me to get this installed by myself . I heard that they did not allow anybody earlier . In this circumstances, can I proceed to get this Grill installed by myself with the same design as others after sending appropriate notice to the Promoter? Is there a chance to get into trouble/legal issues later for this ? Actually, this is bit urgent for me from safety and security purpose as few furniture along with some other items to be delivered to my flat shortly . Please advise .