Certain amount of agreement paid in cash but not returned what to do

Dear Sir, I am a buyer of a property and a seller executed a Regd. Agreement to sale in my name within period of 6 months and I paid him 75% of the Deal price in advance. Before the expiry of the decided time period, I send him 3-4 legal notices to comply with the agreement but he did not turn up to execute sale deed on the date decided as per agreement. I marked my presence in the court along with the rest payment amount cheque of his name. After the expiry of this time period, I found that the seller of property transferred the amount of advance money in my saving account vide RTGS. Now, Please suggest what should I do as my some amount, which I paid in cash is still with him and he only transferred the amount back in my account, which I paid him vide cheque. Is the regd. Agreement will be deemed to get automatically cancelled as the amount I paid him video cheque and mentioned in the agreement is recieved in my account. Can't I file the case of specific performance?