I purchased a ready to move flat on transfer basis

Hi I purchased a flat from someone on transfer basis since he doesn't have done the conveyance deed with the builder yet. Due to this, I was expected to get the house totally as new when taking handover. However builder has taken 8 months from transfer formalities as of now & even after the execution of Conveyance deed happened in Feb'20, builder is delaying to hand it over to my bankers (Property is on Loan) saying it is not yet received from court. Every time I speak to their customer care, they say it is delayed due to lockdown. Due to this I am not able to start my EMIs with homeloan, neither I am getting handover of flat due to not completed the renovation work. Now I have some questions:- 1. How to get the Registry copy & original to handover to bank quickly? As per their mail received for registry formalities, I must have got the copy of conveyance deed before lockdown. 2. How to get the handover of my flat asap? Earlier they have committed this on 22-Apr-2020 however due to lockdown it delayed. But even after lockdown is removed now, they people have not yet started any renovation work on the flat & making excuse of labour issue. Neither they are committing any date in writing. 3. They are still charging me for the Maintenance charges & electricity charges for the same. Get I ask them for the waiver? Even I have paid the Maint. Charges on the behalf of seller, when the property was on his name & deducted the payment from his total payout. Can I claim those charges also since the flat is never handed over to anyone (the ID of account was different at that time)?