Refusal of registration of Sale Deed by Sub Registrar office

A duly stamped SaleDeed (over ₹1crore) for purchase of old flat in a Group Housing Society in Gurugram is signed by vendor and vendee who has availed Home Loan from Bank.The registration fees (₹50k)is already paid on net and challan taken out.Token for registration is taken twice but on both days,Sub Registrar office has refused saying that registration of SaleDeed is obstructed for electronic system failure continuing for SEVERAL MONTHS. Now,we being vendees/Bank borrowers are paying EMI without getting possession of purchased FLAT ,Vendor is demanding DDs with Bank payable to VENDOR for part sale consideration, and lending Bank needs registered SaleDeed for Equitable mortgage,we request you to please advise legal solution HOW in absence of registration for longer uncertain period in future,WITH DULY STAMPED and SIGNED SALE DEED,all the 3 suffering parties i.e.1.Vendee,2.Vendor and 3.Lendor Bank can avoid financial LOSS .Kindly advise us documents on the strength of which Vendor gets their DDs from Bank and give possession of Flat to Vendee and Bank can rely on such Document/s for a wait till SaleDeed is duly registered and is received by the Bank creating an Equitable mortgage.