Supertech Limited — Duplicate payment receipts

We have a flat booked with Supertech Golf country which is still under construction for almost 8 years. We require 3 payment receipts that were misplaced. We are not able to get them from Supertech, extremely unhelpful and rude set of customer support. Since we have put a case against Supertech in RERA court, they are harassing us no end. pls help.