Society Maintenance Query

Hi, I have been living in a society for almost 2 years now. When I purchased the flat I had made an advance payment of 2 years maintenance charges. Now as this period is about to be over, the maintenance charges will start. The society RWA has formed and is in the process to take over the builder CRM. We recently received a maintenance advise from builder CRM (which going forward we will receive from RWA) to make an advance payment of 4 months of maintenance. For my flat the per month maintenance cost is almost 5000 hence 4 months advance will be 20000. I being in a job have a limited income and I pay my EMI, SIPs and run my home expenses too. I am ready to pay monthly maintenance in advance but 4 or 3 month maintenance cost in advance is not possible for me as I will run out of my budget if I pay so much advance. But RWA people are not understanding this thing. Being incapable to pay so much amount in advance (and obviously I wont be taking a loan for maintenance), what if I stand strong that I will only pay monthly maintenance in amount? Can the RWA/Builder CRM deduct it from electricity meter OR poke me in other ways? (Again, I am not denying to pay the maintenance, its just that I am incapable to pay 3/4 months in advance. I am ready to pay monthly advance) Please suggest.