House sale not refunding

Hi Sir, We are staying in an apartment in bangalore. As a flat on same apartment came on resale and we enquired. Owner of the flat was some where in US and his friend was helping him to sell it, so his friend was telling about details of flat. As owners friend told land is Akatha, building is Bkhata and flat don't have occupancy. As we are under impression that land dont have any legal problems. So as a token for booking we gave the owners friend 20000 rs and HD send us a email as receipt, stating he took 20000 rs from us. He gave house documents and we took it to a lawyer, and lawyer told the land is not Akhata before 2006, it has 3 link documents missing. So if go for resale it will be a problem. We checked with them and owners friend told, its true but by that time we already gave him advance. He told us if we are fully satisfied them take the flat, as there was legal problems with bank we backed out. Now they are not ready to repay our advance back. The reason they are giving is for 2 weeks they lost customers. We are the ones who suffered financially as we lost 20k plus lawyer charges 3500 extra. Is there any possible way to get the amount back.