Lift to my flat floor curtailed by another owner

I am a flat owner for 1 flat of 1408 sq ft in first floor and another owner is having 5 flats - 2 in third floor, 2 in second floor and 1 in first floor. After I moved to the flat in June 2024 I discussed with the other owner who is currently maintaining and fixed 29.5 % for me 70.5 % for him of the actual expenses, based on floor area for the monthly maintenance. I asked him to give details of expenses for paying monthly maintenance every month end, but he did not give till now, even after several reminders. Due to this I have not paid the maintenance till now. In addition he was always harassing our family for trivial matters. From November 2024 without any information he curtailed lift use for me for first floor. Myself and my wife are senior citizens and deprived of the facility. I presume that Rs 1500 to Rs 2000 will be charges for me per month. Yesterday he fought with me and demanded for Rs 4000 per month. I told him that as per actual expenses at 29.5% only I can pay and again requested him for the detailed accounts. But he threatened me, said will do something so that I will be paying Rs 4000. Also he said, even if I pay he will not restore lift to my floor. He is a very cunning fellow and not listening to anything when I talk yo him. Please advice what to do