Can builder ask for maintenance charges after possession but ,,

I booked a flat in Punjab from the builder in 2008 and builder offered me the possession in Dec 2012. Delayed possession but builder compensated the amount as per mutual understanding of both. Total flats in the complex is close to 800 and when builder given the physical possession in Feb 2013 construction was going on in the complex. Building got completed in 2015 and builder got the completion certificate from the competent authority in August 2015. RWA is formed in September 2015 but till date handover is not taken from the builder by the RWA. Builder is maintaining the complex. Now my question is Can builder ask for the maintenance charges after giving the possession of the flat but without receiving the completion certificate? Is there any liability for the builder to maintain the complex for one year without any maintenance to be received from the occupants? Can a builder ask for the maintenance charges without signing any maintenance agreement with the flat owner? Builder never raised the individual bill for any maintenance charges, Is it the responsibility of builder to raise a bill for maintenance charges? or builder can ask for maintenance charges with a single notice? Is builder liable to provide the charges of maintenance in detail (Means breakup of maintenance charges) to the occupants of the flat and if he is liable to give and he does not provide the detail and then what are the action can be taken against the builder? Is there any judgements / references available to my above questions either in positive or negative side?