Delayed possession post advance payment due to litigation

I paid advance to builder last year. I did not know at the time that his lease deed was cancelled by High Court. When I came to know, I asked him for refund. He did not give me refund despite assuring on email that he would give refund. This year he got completion certificate Regarding court case, he appealed in supreme court which asked high court to reconsider and this time high court gave ruling in his favour. Meanwhile in the market rates have fallen and rate he signed agreement with me is very high. Also, now service tax is not payable because builder has got completion certificate. But I am not getting this benefit because I entered into transaction before builder receiving completion certificate. Additionally due to delay I suffered loss because I had to stay in rented accommodation. Builder is now saying I should pay him balance amount or he will forfeit my advance. I am asking him to enter into fresh agreement so that service tax is not applicable. Do I have any recourse?