Defaulters in Apartments - Maintenance Payments to Association

I am the Secretary for the Resident Welfare Association of our apartment consisting of 56 units. There is 1 defaulter, who is not paying the dues even after multiple reminders. The association is registered with the Registrar of Societies. I have heard that we cannot disconnect basic amenities like water and electricity. I wanted to clarify, whether the basic amenities, by definition refers to government provided amenities. Like electricity and Govt. water supply. If we do not use Govt. Water supply and the water used by the defaulter is from an onsite borewell, does that mean we can stop that service ? Secondly. We have an STP that provides treated water for usage in Flush tanks in the toilet. There is a separate line that we can close and stop the supply of this treated water. Is this allowed by law. We have already disabled Generator backup supply to this apartment. They are still not paying up. Can we deny the usage of common facilities like swimming pool, club house and gym ? We would like to resort to a suit for recovery after all attempts from our side. Suggestions on how to go about this will be helpful. Right now, the balance due is 68,000/- I am planning the following next steps 1) Issue a notice hard copy on potential impacts if there are no significant payments made regularly to close the outstanding due 2) Receipt of this notice will be documented. 3) A second notice will be sent with the same content as a reminder and receipt of notice by the relevant party will be documented and recorded. 4) Proceed to switch off Treated water supply (STP Water only) to the apartment - If this is allowed by law 5) Deny access to common area facility usage for this resident - if this is allowed by law 6) Restrict water supply to the apartment to 2 hours in the morning and 2 hours in the evening only - if this is allowed by law