Token advance

4 months back i zeroed in to buy a resale flat, on verbal agreement by both parties, we concluded the deal of 68 lakhs for the flat. Seller requested 1 lakh token advance to be paid for which i obliged. When I requested him to sign a acknowledgement for token advance, he said he can't travel to Bangalore from Chennai for 1 lakh token advance, for that he said he will acknowledge via email and he did the same. He provided sale deed and khata and property tax copy to me, since it was not enough from my lawyer to do a complete background check, i requested more documents from him for which he provided few documents and promised he will provide the remaining documents after two weeks, by the time i can get the documents from sub registrar office by myself. Almost after a month's time i arranged most documents then called him, he didn't pick my call and came to know that he sold the property to some other party without my knowledge. I asked the token advance through WhatsApp chat, for which he replied by mail, that it's non refundable generally, but will consider it as an option if I send him a physical letter stating that i have no claims upon receiving the token advance and courier him all the documents i got from him. I feel cheated here since he sold the property without even informing me. But on laws point of view, 1. should he inform me prior selling the flat to another party? 2. Should I do by what i have been instructed by him? 3. Is the token advance not refundable as he mentioned even when he planned to sell the property without informing me? 4. Is there any legal suit i can file for his actions, if yes what are the sections. Kindly provide some information.