Maintenance charges Overdue

I have Flat is in Golden Palm society Noida sector 168 Builder has handed over flat to me in Oct 2017 & taken Maintenance in advance for one year till Sep 2018 . After handling over Flat they have taken payment of other facility like Club house and covered car parking but these facilities handed over after 2 years . I have demanded compensation for delay in possession of facilities because after handed over of facilities my rent increased by 5000 approx. initially they agreed to pay credit note against Maintenance dues . But following up for almost one & half years they are not ready to issue any credit note . During Lock down I have pay cut around 40 % and my husband has lost job and tenant has also left Flat because they misbehave with them due to Maintenance dues . I have written so many emails to higher authorities to waive off previous dues and going forward in future we will pay all charges and facilitates us to rent out flat so that we can maintenance & EMI as well. But they are not ready to settle down & infact threating us . Please help us & provide legal advice to deal with this situation . IF this Flat will be rent we will able to pay Future Maintenance as well as EMI