Owner refuse to sale property

Dear Sir, This is Mohammed from Hyderabad I have purchased a house beside my house and agreed for 36,00,000 in last year Nov-18 and in the agreement we two agreed that sale consideration can complete in six month or can be extended mural from the date of agreement of sale, and in dec-18 I told to take 20,00,000 Lang for which he denied and in may I sent what's up SMS saying that I wanted to extended more six month for which he has not replied I sent again SMS what's up for him and from Aug -19 as I am ready for registration plz confirm when can we close the process, he have not replied and in 30-September 19 he replied that he don't want to sell the property I said fine I paid advance of Rs. 121101 and made expenses to get it Gift deed and tax process for which I gave 4 lakes, I told him we will close as per agreement, as we had one point that if I refuse I will not get advance and if he refuse he had to pay double the advance payment I said pay me 242202 and document charges of 4 lake I will sign on cancellation deed, for he is not ready. Please suggest me what to be done. And I have sent the LEGAL NOTICE to registered owner also.