Society Maintainence Charges Implementation time

Hi, Our project is divided into three phase (9 towers) One phase of the project is completed and posession have been given to the residents. However, Dedicated Parking, Park slots, CCTV and Intercom like basic amenities are not given to us with posession. Builder is still working on the same. Builder has obtained partial completion certificate from local authorities already. I am not sure on Partial OC. However, We are getting services from builder such as security guards, cleaning staff, water, common area lightning, lifts, power backup. In this course we are paying monthly maintenance charges (2400 per month) to builder for these services. As per the articles I had read builder cannot charge maintain charges until he gets occupancy certificate or completion certificate. So my questions are 1. Is it mandatory to pay monthly maintenance charges to the developer on the basis of partial completion certificate? 2. Is maintenance charges can imposed without giving basic amenities such as parking and park? 3. Is it correct that we are paying monthly maintenance charges (rs 2400) to the developer for obtaining above mentioned current services? 4. Is it necessary for builder to obtain partial OC before he starts to change maintenance charges? However, he got the partial completion certificate from local authorities.