Options available after not receiving flat booked in 2014

Hi, I booked flat in Novena Green project located at Noida Extension in October 2013 and agreement paper signed on June 2014, total cost of the flat was 39 lacks and I paid 31.9 lacks till 2016 and then project got stalled due to money issues between the stakeholders, since land was leased from Amarpali so supreme court also further stayed for two years from 2019. Then new promoter called Mangalya came into picture but didn't change the company name(DSD homes) and started looking after the project at snail pace. Buyer went to Rera but Rera applied section 8 and gave builder extended time after time. Recently builder secured funding through SWAMI fund and started construction but now saying pject will be completed on December 2026. Project has 6 towers of 20 floors out of which 3 are already constructed, one till 15 floor, two only 1 floor. I paid 31.9 out of which they are saying you paid 30.9 lacks and 1 lack was bank service tax for online transfer, this is a surprise for me as how come they charge this money from us, is it correct? Now project seems away from possession for another 2 years and Rera court is giving builder time after time what options a common buyer like me has?